diff --git a/apps/lib/cmp_mock_srv.c b/apps/lib/cmp_mock_srv.c
index d58937ea78..edfb1d0c75 100644
--- a/apps/lib/cmp_mock_srv.c
+++ b/apps/lib/cmp_mock_srv.c
@@ -27,7 +27,7 @@ typedef struct
     X509 *oldWithNew;          /* to return in oldWithNew of rootKeyUpdate */
     OSSL_CMP_PKISI *statusOut; /* status for ip/cp/kup/rp msg unless polling */
     int sendError;             /* send error response on given request type */
-    OSSL_CMP_MSG *certReq;     /* ir/cr/p10cr/kur remembered while polling */
+    OSSL_CMP_MSG *req;         /* original request message during polling */
     int pollCount;             /* number of polls before actual cert response */
     int curr_pollCount;        /* number of polls so far for current request */
     int checkAfterTime;        /* time the client should wait between polling */
@@ -43,7 +43,7 @@ static void mock_srv_ctx_free(mock_srv_ctx *ctx)
     X509_free(ctx->certOut);
     OSSL_STACK_OF_X509_free(ctx->chainOut);
     OSSL_STACK_OF_X509_free(ctx->caPubsOut);
-    OSSL_CMP_MSG_free(ctx->certReq);
+    OSSL_CMP_MSG_free(ctx->req);
     OPENSSL_free(ctx);
 }
 
@@ -183,6 +183,44 @@ int ossl_cmp_mock_srv_set_checkAfterTime(OSSL_CMP_SRV_CTX *srv_ctx, int sec)
     return 1;
 }
 
+static int delayed_delivery(OSSL_CMP_SRV_CTX *srv_ctx,
+                            const OSSL_CMP_MSG *req)
+{
+    mock_srv_ctx *ctx = OSSL_CMP_SRV_CTX_get0_custom_ctx(srv_ctx);
+    int req_type = OSSL_CMP_MSG_get_bodytype(req);
+
+    if (ctx == NULL || req == NULL) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
+        return 0;
+    }
+
+    /*
+     * For ir/cr/p10cr/kur delayed delivery is handled separately in
+     * process_cert_request
+     */
+    if (req_type == OSSL_CMP_IR
+        || req_type == OSSL_CMP_CR
+        || req_type == OSSL_CMP_P10CR
+        || req_type == OSSL_CMP_KUR
+        /* Client may use error to abort the ongoing polling */
+        || req_type == OSSL_CMP_ERROR)
+        return 0;
+
+    if (ctx->pollCount > 0 && ctx->curr_pollCount == 0) {
+        /* start polling */
+        if (ctx->req != NULL) { /* TODO: move this check to cmp_server.c */
+            /* already in polling mode */
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+            return 0;
+        }
+        if ((ctx->req = OSSL_CMP_MSG_dup(req)) == NULL)
+            return -1;
+
+        return 1;
+    }
+    return 0;
+}
+
 /* check for matching reference cert components, as far as given */
 static int refcert_cmp(const X509 *refcert,
                        const X509_NAME *issuer, const ASN1_INTEGER *serial)
@@ -198,6 +236,23 @@ static int refcert_cmp(const X509 *refcert,
         && (ref_serial == NULL || ASN1_INTEGER_cmp(serial, ref_serial) == 0);
 }
 
+/* Reset dynamic variable in case of incomplete tansaction */
+static int reset_transaction(OSSL_CMP_SRV_CTX *srv_ctx)
+{
+    mock_srv_ctx *ctx = NULL;
+
+    if (srv_ctx == NULL) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
+        return 0;
+    }
+
+    ctx = OSSL_CMP_SRV_CTX_get0_custom_ctx(srv_ctx);
+    ctx->curr_pollCount = 0;
+    OSSL_CMP_MSG_free(ctx->req);
+    ctx->req = NULL;
+    return 1;
+}
+
 static OSSL_CMP_PKISI *process_cert_request(OSSL_CMP_SRV_CTX *srv_ctx,
                                             const OSSL_CMP_MSG *cert_req,
                                             ossl_unused int certReqId,
@@ -228,12 +283,12 @@ static OSSL_CMP_PKISI *process_cert_request(OSSL_CMP_SRV_CTX *srv_ctx,
 
     if (ctx->pollCount > 0 && ctx->curr_pollCount == 0) {
         /* start polling */
-        if (ctx->certReq != NULL) {
+        if (ctx->req != NULL) {
             /* already in polling mode */
             ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
             return NULL;
         }
-        if ((ctx->certReq = OSSL_CMP_MSG_dup(cert_req)) == NULL)
+        if ((ctx->req = OSSL_CMP_MSG_dup(cert_req)) == NULL)
             return NULL;
         return OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_waiting, 0, NULL);
     }
@@ -481,35 +536,35 @@ static int process_certConf(OSSL_CMP_SRV_CTX *srv_ctx,
 static int process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
                            const OSSL_CMP_MSG *pollReq,
                            ossl_unused int certReqId,
-                           OSSL_CMP_MSG **certReq, int64_t *check_after)
+                           OSSL_CMP_MSG **req, int64_t *check_after)
 {
     mock_srv_ctx *ctx = OSSL_CMP_SRV_CTX_get0_custom_ctx(srv_ctx);
 
     if (ctx == NULL || pollReq == NULL
-            || certReq == NULL || check_after == NULL) {
+            || req == NULL || check_after == NULL) {
         ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
         return 0;
     }
     if (ctx->sendError == 1
             || ctx->sendError == OSSL_CMP_MSG_get_bodytype(pollReq)) {
-        *certReq = NULL;
+        *req = NULL;
         ERR_raise(ERR_LIB_CMP, CMP_R_ERROR_PROCESSING_MESSAGE);
         return 0;
     }
-    if (ctx->certReq == NULL) {
+    if (ctx->req == NULL) { /* TODO: move this check to cmp_server.c */
         /* not currently in polling mode */
-        *certReq = NULL;
+        *req = NULL;
         ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
         return 0;
     }
 
     if (++ctx->curr_pollCount >= ctx->pollCount) {
         /* end polling */
-        *certReq = ctx->certReq;
-        ctx->certReq = NULL;
+        *req = ctx->req;
+        ctx->req = NULL;
         *check_after = 0;
     } else {
-        *certReq = NULL;
+        *req = NULL;
         *check_after = ctx->checkAfterTime;
     }
     return 1;
@@ -523,7 +578,9 @@ OSSL_CMP_SRV_CTX *ossl_cmp_mock_srv_new(OSSL_LIB_CTX *libctx, const char *propq)
     if (srv_ctx != NULL && ctx != NULL
             && OSSL_CMP_SRV_CTX_init(srv_ctx, ctx, process_cert_request,
                                      process_rr, process_genm, process_error,
-                                     process_certConf, process_pollReq))
+                                     process_certConf, process_pollReq)
+            && OSSL_CMP_SRV_CTX_setup_polling(srv_ctx, reset_transaction,
+                                              delayed_delivery))
         return srv_ctx;
 
     mock_srv_ctx_free(ctx);
diff --git a/crypto/cmp/cmp_client.c b/crypto/cmp/cmp_client.c
index b5b0557b0d..cf352c9d71 100644
--- a/crypto/cmp/cmp_client.c
+++ b/crypto/cmp/cmp_client.c
@@ -113,6 +113,23 @@ static int save_statusInfo(OSSL_CMP_CTX *ctx, OSSL_CMP_PKISI *si)
     return 1;
 }
 
+static int is_crep_with_waiting(OSSL_CMP_MSG *resp, int rid)
+{
+    OSSL_CMP_CERTREPMESSAGE *crepmsg;
+    OSSL_CMP_CERTRESPONSE *crep;
+    int bt = OSSL_CMP_MSG_get_bodytype(resp);
+
+    if (!IS_CREP(bt))
+        return 0;
+
+    crepmsg = resp->body->value.ip; /* same for cp and kup */
+    crep = ossl_cmp_certrepmessage_get0_certresponse(crepmsg, rid);
+
+    return (crep != NULL
+            && ossl_cmp_pkisi_get_status(crep->status)
+            == OSSL_CMP_PKISTATUS_waiting);
+}
+
 /*-
  * Perform the generic aspects of sending a request and receiving a response.
  * Returns 1 on success and provides the received PKIMESSAGE in *rep.
@@ -180,7 +197,8 @@ static int send_receive_check(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
      * Still we use this preliminary value already for a progress report because
      * the following msg verification may also produce log entries and may fail.
      */
-    ossl_cmp_log1(INFO, ctx, "received %s", ossl_cmp_bodytype_to_string(bt));
+    ossl_cmp_log2(INFO, ctx, "received %s%s", ossl_cmp_bodytype_to_string(bt),
+                  ossl_cmp_is_error_with_waiting(*rep) ? " (waiting)" : "");
 
     /* copy received extraCerts to ctx->extraCertsIn so they can be retrieved */
     if (bt != OSSL_CMP_PKIBODY_POLLREP && bt != OSSL_CMP_PKIBODY_PKICONF
@@ -191,9 +209,17 @@ static int send_receive_check(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
                                    expected_type))
         return 0;
 
+    /*
+     * 'rep' can have the expected response type, which during polling is
+     * pollRep. When polling, also any other non-error response (the final
+     * response) is fine here. When not yet polling, delayed delivery may
+     * be started by an error with 'waiting' status (while it may also be
+     * started by an expected response type ip/cp/kup).
+     */
     if (bt == expected_type
-        /* as an answer to polling, there could be IP/CP/KUP: */
-            || (IS_CREP(bt) && expected_type == OSSL_CMP_PKIBODY_POLLREP))
+        || (expected_type == OSSL_CMP_PKIBODY_POLLREP
+            ? bt != OSSL_CMP_PKIBODY_ERROR
+            : ossl_cmp_is_error_with_waiting(*rep)))
         return 1;
 
     /* received message type is not one of the expected ones (e.g., error) */
@@ -235,7 +261,7 @@ static int send_receive_check(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
 
 /*-
  * When a 'waiting' PKIStatus has been received, this function is used to
- * poll, which should yield a pollRep or finally a CertRepMessage in ip/cp/kup.
+ * poll, which should yield a pollRep or the final response.
  * On receiving a pollRep, which includes a checkAfter value, it return this
  * value if sleep == 0, else it sleeps as long as indicated and retries.
  *
@@ -246,7 +272,8 @@ static int send_receive_check(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
  * Returns -1 on receiving pollRep if sleep == 0, setting the checkAfter value.
  * Returns 1 on success and provides the received PKIMESSAGE in *rep.
  *           In this case the caller is responsible for freeing *rep.
- * Returns 0 on error (which includes the case that timeout has been reached).
+ * Returns 0 on error (which includes the case that timeout has been reached or
+ *           received response with waiting status).
  */
 static int poll_for_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
                              OSSL_CMP_MSG **rep, int *checkAfter)
@@ -312,7 +339,7 @@ static int poll_for_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
                           str, check_after);
 
             if (ctx->total_timeout != 0) { /* timeout is not infinite */
-                const int exp = 5; /* expected max time per msg round trip */
+                const int exp = OSSL_CMP_EXPECTED_RESP_TIME;
                 int64_t time_left = (int64_t)(ctx->end_time - exp - time(NULL));
 
                 if (time_left <= 0) {
@@ -335,9 +362,19 @@ static int poll_for_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
                     *checkAfter = (int)check_after;
                 return -1; /* exits the loop */
             }
+        } else if (is_crep_with_waiting(prep, rid)
+                   || ossl_cmp_is_error_with_waiting(prep)) {
+            /* status cannot be 'waiting' at this point */
+            (void)ossl_cmp_exchange_error(ctx, OSSL_CMP_PKISTATUS_rejection,
+                                          OSSL_CMP_CTX_FAILINFO_badRequest,
+                                          "polling already started",
+                                          0 /* errorCode */, NULL);
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKISTATUS);
+            goto err;
         } else {
-            ossl_cmp_info(ctx, "received ip/cp/kup after polling");
-            /* any other body type has been rejected by send_receive_check() */
+            ossl_cmp_info(ctx, "received final response after polling");
+            if (!ossl_cmp_ctx_set1_first_senderNonce(ctx, NULL))
+                return 0;
             break;
         }
     }
@@ -349,11 +386,66 @@ static int poll_for_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
 
     return 1;
  err:
+    (void)ossl_cmp_ctx_set1_first_senderNonce(ctx, NULL);
     OSSL_CMP_MSG_free(preq);
     OSSL_CMP_MSG_free(prep);
     return 0;
 }
 
+static int save_senderNonce_if_waiting(OSSL_CMP_CTX *ctx,
+                                       OSSL_CMP_MSG *rep, int rid)
+{
+    /*
+     * LWCMP section 4.4 states: the senderNonce of the preceding request
+     * message because this value will be needed for checking the recipNonce
+     * of the final response to be received after polling.
+     */
+    if ((is_crep_with_waiting(rep, rid)
+         || ossl_cmp_is_error_with_waiting(rep))
+        && !ossl_cmp_ctx_set1_first_senderNonce(ctx, ctx->senderNonce))
+        return 0;
+
+    return 1;
+}
+
+/*
+ * send request and get response possibly with polling initiated by error msg.
+ * Polling for ip/cp/kup/ with 'waiting' status is handled elsewhere.
+ */
+static int send_receive_also_delayed(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *req,
+                                     OSSL_CMP_MSG **rep, int expected_type)
+{
+
+    if (!send_receive_check(ctx, req, rep, expected_type))
+        return 0;
+
+    if (ossl_cmp_is_error_with_waiting(*rep)) {
+        if (!save_senderNonce_if_waiting(ctx, *rep, -1 /* rid */))
+            return 0;
+        /*
+         * not modifying ctx->status during the certConf & error exchange,
+         * because these additional exchanges should not change the status.
+         */
+        if (expected_type != OSSL_CMP_PKIBODY_PKICONF
+            && !save_statusInfo(ctx, (*rep)->body->value.error->pKIStatusInfo))
+            return 0;
+
+        OSSL_CMP_MSG_free(*rep);
+        *rep = NULL;
+
+        if (poll_for_response(ctx, 1 /* can sleep */, -1 /* rid */,
+                              rep, NULL /* checkAfter */) <= 0) {
+            ERR_raise(ERR_LIB_CMP, CMP_R_POLLING_FAILED);
+            return 0;
+        }
+    }
+    if (OSSL_CMP_MSG_get_bodytype(*rep) != expected_type) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        return 0;
+    }
+
+    return 1;
+}
 /*
  * Send certConf for IR, CR or KUR sequences and check response,
  * not modifying ctx->status during the certConf exchange
@@ -370,7 +462,8 @@ int ossl_cmp_exchange_certConf(OSSL_CMP_CTX *ctx, int certReqId,
     if (certConf == NULL)
         goto err;
 
-    res = send_receive_check(ctx, certConf, &PKIconf, OSSL_CMP_PKIBODY_PKICONF);
+    res = send_receive_also_delayed(ctx, certConf,
+                                    &PKIconf, OSSL_CMP_PKIBODY_PKICONF);
 
  err:
     OSSL_CMP_MSG_free(certConf);
@@ -394,7 +487,8 @@ int ossl_cmp_exchange_error(OSSL_CMP_CTX *ctx, int status, int fail_info,
     if ((error = ossl_cmp_error_new(ctx, si, errorCode, details, 0)) == NULL)
         goto err;
 
-    res = send_receive_check(ctx, error, &PKIconf, OSSL_CMP_PKIBODY_PKICONF);
+    res = send_receive_also_delayed(ctx, error,
+                                    &PKIconf, OSSL_CMP_PKIBODY_PKICONF);
 
  err:
     OSSL_CMP_MSG_free(error);
@@ -515,7 +609,7 @@ int OSSL_CMP_certConf_cb(OSSL_CMP_CTX *ctx, X509 *cert, int fail_info,
         if (X509_verify_cert(csc) <= 0)
             goto err;
 
-        if (!ossl_x509_add_certs_new(&chain,  X509_STORE_CTX_get0_chain(csc),
+        if (!ossl_x509_add_certs_new(&chain, X509_STORE_CTX_get0_chain(csc),
                                      X509_ADD_FLAG_UP_REF | X509_ADD_FLAG_NO_DUP
                                      | X509_ADD_FLAG_NO_SS)) {
             sk_X509_free(chain);
@@ -564,48 +658,74 @@ static int cert_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
     EVP_PKEY *rkey = ossl_cmp_ctx_get0_newPubkey(ctx);
     int fail_info = 0; /* no failure */
     const char *txt = NULL;
-    OSSL_CMP_CERTREPMESSAGE *crepmsg;
-    OSSL_CMP_CERTRESPONSE *crep;
+    OSSL_CMP_CERTREPMESSAGE *crepmsg = NULL;
+    OSSL_CMP_CERTRESPONSE *crep = NULL;
     OSSL_CMP_certConf_cb_t cb;
     X509 *cert;
     char *subj = NULL;
     int ret = 1;
+    int rcvd_type;
+    OSSL_CMP_PKISI *si;
 
     if (!ossl_assert(ctx != NULL))
         return 0;
 
  retry:
-    crepmsg = (*resp)->body->value.ip; /* same for cp and kup */
-    if (sk_OSSL_CMP_CERTRESPONSE_num(crepmsg->response) > 1) {
-        ERR_raise(ERR_LIB_CMP, CMP_R_MULTIPLE_RESPONSES_NOT_SUPPORTED);
-        return 0;
-    }
-    crep = ossl_cmp_certrepmessage_get0_certresponse(crepmsg, rid);
-    if (crep == NULL)
-        return 0;
-    if (!save_statusInfo(ctx, crep->status))
-        return 0;
-    if (rid == OSSL_CMP_CERTREQID_NONE) { /* used for OSSL_CMP_PKIBODY_P10CR */
-        rid = ossl_cmp_asn1_get_int(crep->certReqId);
-        if (rid < OSSL_CMP_CERTREQID_NONE) {
-            ERR_raise(ERR_LIB_CMP, CMP_R_BAD_REQUEST_ID);
+    rcvd_type = OSSL_CMP_MSG_get_bodytype(*resp);
+    if (IS_CREP(rcvd_type)) {
+        crepmsg = (*resp)->body->value.ip; /* same for cp and kup */
+        if (sk_OSSL_CMP_CERTRESPONSE_num(crepmsg->response) > 1) {
+            ERR_raise(ERR_LIB_CMP, CMP_R_MULTIPLE_RESPONSES_NOT_SUPPORTED);
             return 0;
         }
+        crep = ossl_cmp_certrepmessage_get0_certresponse(crepmsg, rid);
+        if (crep == NULL)
+            return 0;
+        si = crep->status;
+
+        if (rid ==  OSSL_CMP_CERTREQID_NONE) {
+            /* for OSSL_CMP_PKIBODY_P10CR learn CertReqId from response */
+            rid = ossl_cmp_asn1_get_int(crep->certReqId);
+            if (rid ==  OSSL_CMP_CERTREQID_NONE) {
+                ERR_raise(ERR_LIB_CMP, CMP_R_BAD_REQUEST_ID);
+                return 0;
+            }
+        }
+    } else if (rcvd_type == OSSL_CMP_PKIBODY_ERROR) {
+        si = (*resp)->body->value.error->pKIStatusInfo;
+    } else {
+        ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        return 0;
     }
 
-    if (ossl_cmp_pkisi_get_status(crep->status) == OSSL_CMP_PKISTATUS_waiting) {
+    if (!save_statusInfo(ctx, si))
+        return 0;
+
+    if (ossl_cmp_pkisi_get_status(si) == OSSL_CMP_PKISTATUS_waiting) {
+        /* here we allow different flavor of ip/cp/kup & error with waiting */
         OSSL_CMP_MSG_free(*resp);
         *resp = NULL;
         if ((ret = poll_for_response(ctx, sleep, rid, resp, checkAfter)) != 0) {
             if (ret == -1) /* at this point implies sleep == 0 */
                 return ret; /* waiting */
-            goto retry; /* got ip/cp/kup, which may still indicate 'waiting' */
+            goto retry; /* got some response other than pollRep */
         } else {
             ERR_raise(ERR_LIB_CMP, CMP_R_POLLING_FAILED);
             return 0;
         }
     }
 
+    /* at this point, ip/cp/kup or error without waiting */
+    if (rcvd_type == OSSL_CMP_PKIBODY_ERROR) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_RECEIVED_ERROR);
+        return 0;
+    }
+    /* here we are strict on the flavor of ip/cp/kup */
+    if (rcvd_type != expected_type) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        return 0;
+    }
+
     cert = get1_cert_status(ctx, (*resp)->body->type, crep);
     if (cert == NULL) {
         ERR_add_error_data(1, "; cannot extract certificate from response");
@@ -618,7 +738,8 @@ static int cert_response(OSSL_CMP_CTX *ctx, int sleep, int rid,
      * if the CMP server returned certificates in the caPubs field, copy them
      * to the context so that they can be retrieved if necessary
      */
-    if (crepmsg->caPubs != NULL
+    if (crepmsg != NULL
+            && crepmsg->caPubs != NULL
             && !ossl_cmp_ctx_set1_caPubs(ctx, crepmsg->caPubs))
         return 0;
 
@@ -709,6 +830,9 @@ int OSSL_CMP_try_certreq(OSSL_CMP_CTX *ctx, int req_type,
     if (ctx->status != OSSL_CMP_PKISTATUS_waiting) { /* not polling already */
         if (!initial_certreq(ctx, req_type, crm, &rep, rep_type))
             goto err;
+
+        if (!save_senderNonce_if_waiting(ctx, rep, rid))
+            return 0;
     } else {
         if (req_type < 0)
             return ossl_cmp_exchange_error(ctx, OSSL_CMP_PKISTATUS_rejection,
@@ -750,6 +874,9 @@ X509 *OSSL_CMP_exec_certreq(OSSL_CMP_CTX *ctx, int req_type,
     if (!initial_certreq(ctx, req_type, crm, &rep, rep_type))
         goto err;
 
+    if (!save_senderNonce_if_waiting(ctx, rep, rid))
+        return 0;
+
     if (cert_response(ctx, 1 /* sleep */, rid, &rep, NULL, req_type, rep_type)
         <= 0)
         goto err;
@@ -787,7 +914,7 @@ int OSSL_CMP_exec_RR_ses(OSSL_CMP_CTX *ctx)
         goto end;
 
     ctx->status = OSSL_CMP_PKISTATUS_trans;
-    if (!send_receive_check(ctx, rr, &rp, OSSL_CMP_PKIBODY_RP))
+    if (!send_receive_also_delayed(ctx, rr, &rp, OSSL_CMP_PKIBODY_RP))
         goto end;
 
     rrep = rp->body->value.rp;
@@ -908,7 +1035,7 @@ STACK_OF(OSSL_CMP_ITAV) *OSSL_CMP_exec_GENM_ses(OSSL_CMP_CTX *ctx)
         goto err;
 
     ctx->status = OSSL_CMP_PKISTATUS_trans;
-    if (!send_receive_check(ctx, genm, &genp, OSSL_CMP_PKIBODY_GENP))
+    if (!send_receive_also_delayed(ctx, genm, &genp, OSSL_CMP_PKIBODY_GENP))
         goto err;
     ctx->status = OSSL_CMP_PKISTATUS_accepted;
 
diff --git a/crypto/cmp/cmp_ctx.c b/crypto/cmp/cmp_ctx.c
index 5e542200e9..cc62ae4e4e 100644
--- a/crypto/cmp/cmp_ctx.c
+++ b/crypto/cmp/cmp_ctx.c
@@ -183,6 +183,7 @@ int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx)
         && ossl_cmp_ctx_set1_caPubs(ctx, NULL)
         && ossl_cmp_ctx_set1_extraCertsIn(ctx, NULL)
         && ossl_cmp_ctx_set1_validatedSrvCert(ctx, NULL)
+        && ossl_cmp_ctx_set1_first_senderNonce(ctx, NULL)
         && OSSL_CMP_CTX_set1_transactionID(ctx, NULL)
         && OSSL_CMP_CTX_set1_senderNonce(ctx, NULL)
         && ossl_cmp_ctx_set1_recipNonce(ctx, NULL);
@@ -226,6 +227,7 @@ void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx)
     ASN1_OCTET_STRING_free(ctx->transactionID);
     ASN1_OCTET_STRING_free(ctx->senderNonce);
     ASN1_OCTET_STRING_free(ctx->recipNonce);
+    ASN1_OCTET_STRING_free(ctx->first_senderNonce);
     OSSL_CMP_ITAVs_free(ctx->geninfo_ITAVs);
     OSSL_STACK_OF_X509_free(ctx->extraCertsOut);
 
@@ -814,6 +816,9 @@ DEFINE_set1_ASN1_OCTET_STRING(ossl_cmp_ctx, recipNonce)
 /* Stores the given nonce as the last senderNonce sent out */
 DEFINE_set1_ASN1_OCTET_STRING(OSSL_CMP_CTX, senderNonce)
 
+/* store the first req sender nonce for verifying delayed delivery */
+DEFINE_set1_ASN1_OCTET_STRING(ossl_cmp_ctx, first_senderNonce)
+
 /* Set the proxy server to use for HTTP(S) connections */
 DEFINE_OSSL_CMP_CTX_set1(proxy, char)
 
diff --git a/crypto/cmp/cmp_local.h b/crypto/cmp/cmp_local.h
index b8da48ac43..175cc2575c 100644
--- a/crypto/cmp/cmp_local.h
+++ b/crypto/cmp/cmp_local.h
@@ -95,6 +95,7 @@ struct ossl_cmp_ctx_st {
     ASN1_OCTET_STRING *transactionID; /* the current transaction ID */
     ASN1_OCTET_STRING *senderNonce; /* last nonce sent */
     ASN1_OCTET_STRING *recipNonce; /* last nonce received */
+    ASN1_OCTET_STRING *first_senderNonce; /* sender nonce when starting to poll */
     ASN1_UTF8STRING *freeText; /* optional string to include each msg */
     STACK_OF(OSSL_CMP_ITAV) *geninfo_ITAVs;
     int implicitConfirm; /* set implicitConfirm in IR/KUR/CR messages */
@@ -823,6 +824,8 @@ int ossl_cmp_ctx_set1_extraCertsIn(OSSL_CMP_CTX *ctx,
 int ossl_cmp_ctx_set1_recipNonce(OSSL_CMP_CTX *ctx,
                                  const ASN1_OCTET_STRING *nonce);
 EVP_PKEY *ossl_cmp_ctx_get0_newPubkey(const OSSL_CMP_CTX *ctx);
+int ossl_cmp_ctx_set1_first_senderNonce(OSSL_CMP_CTX *ctx,
+                                        const ASN1_OCTET_STRING *nonce);
 
 /* from cmp_status.c */
 int ossl_cmp_pkisi_get_status(const OSSL_CMP_PKISI *si);
@@ -939,6 +942,7 @@ ossl_cmp_certrepmessage_get0_certresponse(const OSSL_CMP_CERTREPMESSAGE *crm,
 X509 *ossl_cmp_certresponse_get1_cert(const OSSL_CMP_CTX *ctx,
                                       const OSSL_CMP_CERTRESPONSE *crep);
 OSSL_CMP_MSG *ossl_cmp_msg_load(const char *file);
+int ossl_cmp_is_error_with_waiting(const OSSL_CMP_MSG *msg);
 
 /* from cmp_protect.c */
 int ossl_cmp_msg_add_extraCerts(OSSL_CMP_CTX *ctx, OSSL_CMP_MSG *msg);
@@ -958,6 +962,8 @@ int ossl_cmp_verify_popo(const OSSL_CMP_CTX *ctx,
                          const OSSL_CMP_MSG *msg, int accept_RAVerified);
 
 /* from cmp_client.c */
+/* expected max time per msg round trip, used for last try during polling: */
+# define OSSL_CMP_EXPECTED_RESP_TIME 2
 int ossl_cmp_exchange_certConf(OSSL_CMP_CTX *ctx, int certReqId,
                                int fail_info, const char *txt);
 int ossl_cmp_exchange_error(OSSL_CMP_CTX *ctx, int status, int fail_info,
diff --git a/crypto/cmp/cmp_msg.c b/crypto/cmp/cmp_msg.c
index e00afc809e..1b9e275d7a 100644
--- a/crypto/cmp/cmp_msg.c
+++ b/crypto/cmp/cmp_msg.c
@@ -1200,3 +1200,13 @@ int i2d_OSSL_CMP_MSG_bio(BIO *bio, const OSSL_CMP_MSG *msg)
 {
     return ASN1_i2d_bio_of(OSSL_CMP_MSG, i2d_OSSL_CMP_MSG, bio, msg);
 }
+
+int ossl_cmp_is_error_with_waiting(const OSSL_CMP_MSG *msg)
+{
+    if (!ossl_assert(msg != NULL))
+        return 0;
+
+    return (OSSL_CMP_MSG_get_bodytype(msg) == OSSL_CMP_PKIBODY_ERROR
+            && ossl_cmp_pkisi_get_status(msg->body->value.error->pKIStatusInfo)
+            == OSSL_CMP_PKISTATUS_waiting);
+}
diff --git a/crypto/cmp/cmp_server.c b/crypto/cmp/cmp_server.c
index 06ef8fbb61..1e3ca15e89 100644
--- a/crypto/cmp/cmp_server.c
+++ b/crypto/cmp/cmp_server.c
@@ -32,6 +32,8 @@ struct ossl_cmp_srv_ctx_st
     OSSL_CMP_SRV_error_cb_t process_error;
     OSSL_CMP_SRV_certConf_cb_t process_certConf;
     OSSL_CMP_SRV_pollReq_cb_t process_pollReq;
+    OSSL_CMP_SRV_reset_transaction_cb_t reset_transaction;
+    OSSL_CMP_SRV_delayed_delivery_cb_t delayed_delivery;
 
     int sendUnprotectedErrors; /* Send error and rejection msgs unprotected */
     int acceptUnprotected;     /* Accept requests with no/invalid prot. */
@@ -89,6 +91,19 @@ int OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX *srv_ctx, void *custom_ctx,
     return 1;
 }
 
+int OSSL_CMP_SRV_CTX_setup_polling(OSSL_CMP_SRV_CTX *srv_ctx,
+                                   OSSL_CMP_SRV_reset_transaction_cb_t reset_transaction,
+                                   OSSL_CMP_SRV_delayed_delivery_cb_t delayed_delivery)
+{
+    if (srv_ctx == NULL) {
+        ERR_raise(ERR_LIB_CMP, CMP_R_NULL_ARGUMENT);
+        return 0;
+    }
+    srv_ctx->reset_transaction = reset_transaction;
+    srv_ctx->delayed_delivery = delayed_delivery;
+    return 1;
+}
+
 OSSL_CMP_CTX *OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX *srv_ctx)
 {
     if (srv_ctx == NULL) {
@@ -149,6 +164,32 @@ int OSSL_CMP_SRV_CTX_set_grant_implicit_confirm(OSSL_CMP_SRV_CTX *srv_ctx,
     return 1;
 }
 
+/* Return error msg with waiting status if polling is initiated, else NULL. */
+static OSSL_CMP_MSG *delayed_delivery(OSSL_CMP_SRV_CTX *srv_ctx,
+                                      const OSSL_CMP_MSG *req)
+{
+    OSSL_CMP_MSG *msg = NULL;
+    OSSL_CMP_PKISI *si = NULL;
+    int ret;
+
+    if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL
+                     && srv_ctx->delayed_delivery != NULL))
+        return NULL;
+
+    ret = srv_ctx->delayed_delivery(srv_ctx, req);
+    if (ret == 0 || !ossl_assert(ret != -1))
+        return NULL;
+
+    if ((si = OSSL_CMP_STATUSINFO_new(OSSL_CMP_PKISTATUS_waiting, 0, NULL))
+        == NULL)
+        return NULL;
+
+    msg = ossl_cmp_error_new(srv_ctx->ctx, si, 0,
+                             NULL, srv_ctx->sendUnprotectedErrors);
+    OSSL_CMP_PKISI_free(si);
+    return msg;
+}
+
 /*
  * Processes an ir/cr/p10cr/kur and returns a certification response.
  * Only handles the first certification request contained in req
@@ -387,13 +428,66 @@ static OSSL_CMP_MSG *process_certConf(OSSL_CMP_SRV_CTX *srv_ctx,
     return msg;
 }
 
+/* pollreq should be handled separately, to avoid recursive call */
+static OSSL_CMP_MSG *process_non_polling_request(OSSL_CMP_SRV_CTX *srv_ctx,
+                                                 const OSSL_CMP_MSG *req)
+{
+    OSSL_CMP_MSG *rsp = NULL;
+
+    if (!ossl_assert(srv_ctx != NULL && srv_ctx->ctx != NULL && req != NULL
+                     && req->body != NULL))
+        return NULL;
+
+    switch (OSSL_CMP_MSG_get_bodytype(req)) {
+    case OSSL_CMP_PKIBODY_IR:
+    case OSSL_CMP_PKIBODY_CR:
+    case OSSL_CMP_PKIBODY_P10CR:
+    case OSSL_CMP_PKIBODY_KUR:
+        if (srv_ctx->process_cert_request == NULL)
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        else
+            rsp = process_cert_request(srv_ctx, req);
+        break;
+    case OSSL_CMP_PKIBODY_RR:
+        if (srv_ctx->process_rr == NULL)
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        else
+            rsp = process_rr(srv_ctx, req);
+        break;
+    case OSSL_CMP_PKIBODY_GENM:
+        if (srv_ctx->process_genm == NULL)
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        else
+            rsp = process_genm(srv_ctx, req);
+        break;
+    case OSSL_CMP_PKIBODY_ERROR:
+        if (srv_ctx->process_error == NULL)
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        else
+            rsp = process_error(srv_ctx, req);
+        break;
+    case OSSL_CMP_PKIBODY_CERTCONF:
+        if (srv_ctx->process_certConf == NULL)
+            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        else
+            rsp = process_certConf(srv_ctx, req);
+        break;
+    default:
+        /* Other request message types are not supported */
+        ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
+        break;
+    }
+
+    return rsp;
+}
+
 static OSSL_CMP_MSG *process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
                                      const OSSL_CMP_MSG *req)
 {
     OSSL_CMP_POLLREQCONTENT *prc;
     OSSL_CMP_POLLREQ *pr;
     int certReqId;
-    OSSL_CMP_MSG *certReq;
+    OSSL_CMP_MSG *orig_req;
     int64_t check_after = 0;
     OSSL_CMP_MSG *msg = NULL;
 
@@ -413,12 +507,12 @@ static OSSL_CMP_MSG *process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
         return NULL;
     }
     if (!srv_ctx->process_pollReq(srv_ctx, req, certReqId,
-                                  &certReq, &check_after))
+                                  &orig_req, &check_after))
         return NULL;
 
-    if (certReq != NULL) {
-        msg = process_cert_request(srv_ctx, certReq);
-        OSSL_CMP_MSG_free(certReq);
+    if (orig_req != NULL) {
+        msg = process_non_polling_request(srv_ctx, orig_req);
+        OSSL_CMP_MSG_free(orig_req);
     } else {
         if ((msg = ossl_cmp_pollRep_new(srv_ctx->ctx, certReqId,
                                         check_after)) == NULL)
@@ -509,6 +603,10 @@ OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
         if (!OSSL_CMP_CTX_set1_transactionID(ctx, NULL)
                 || !OSSL_CMP_CTX_set1_senderNonce(ctx, NULL))
             goto err;
+
+        if (srv_ctx->reset_transaction != NULL)
+            (void)srv_ctx->reset_transaction(srv_ctx);
+
         break;
     default:
         /* transactionID should be already initialized */
@@ -528,50 +626,17 @@ OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
     if (!req_verified)
         goto err;
 
-    switch (req_type) {
-    case OSSL_CMP_PKIBODY_IR:
-    case OSSL_CMP_PKIBODY_CR:
-    case OSSL_CMP_PKIBODY_P10CR:
-    case OSSL_CMP_PKIBODY_KUR:
-        if (srv_ctx->process_cert_request == NULL)
-            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        else
-            rsp = process_cert_request(srv_ctx, req);
-        break;
-    case OSSL_CMP_PKIBODY_RR:
-        if (srv_ctx->process_rr == NULL)
-            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        else
-            rsp = process_rr(srv_ctx, req);
-        break;
-    case OSSL_CMP_PKIBODY_GENM:
-        if (srv_ctx->process_genm == NULL)
-            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        else
-            rsp = process_genm(srv_ctx, req);
-        break;
-    case OSSL_CMP_PKIBODY_ERROR:
-        if (srv_ctx->process_error == NULL)
-            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        else
-            rsp = process_error(srv_ctx, req);
-        break;
-    case OSSL_CMP_PKIBODY_CERTCONF:
-        if (srv_ctx->process_certConf == NULL)
-            ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        else
-            rsp = process_certConf(srv_ctx, req);
-        break;
-    case OSSL_CMP_PKIBODY_POLLREQ:
+    if (req_type == OSSL_CMP_PKIBODY_POLLREQ) {
         if (srv_ctx->process_pollReq == NULL)
             ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
         else
             rsp = process_pollReq(srv_ctx, req);
-        break;
-    default:
-        /* Other request message types are not supported */
-        ERR_raise(ERR_LIB_CMP, CMP_R_UNEXPECTED_PKIBODY);
-        break;
+    } else {
+        if (srv_ctx->delayed_delivery != NULL
+            && (rsp = delayed_delivery(srv_ctx, req)) != NULL) {
+            goto err;
+        }
+        rsp = process_non_polling_request(srv_ctx, req);
     }
 
  err:
@@ -627,15 +692,22 @@ OSSL_CMP_MSG *OSSL_CMP_SRV_process_request(OSSL_CMP_SRV_CTX *srv_ctx,
             break;
         /* fall through */
 
+    case OSSL_CMP_PKIBODY_ERROR:
+        if (rsp != NULL
+            && ossl_cmp_is_error_with_waiting(rsp))
+            break;
+        /* fall through */
+
     case OSSL_CMP_PKIBODY_RP:
     case OSSL_CMP_PKIBODY_PKICONF:
     case OSSL_CMP_PKIBODY_GENP:
-    case OSSL_CMP_PKIBODY_ERROR:
         /* Other terminating response message types are not supported */
         /* Prepare for next transaction, ignoring any errors here: */
         (void)OSSL_CMP_CTX_set1_transactionID(ctx, NULL);
         (void)OSSL_CMP_CTX_set1_senderNonce(ctx, NULL);
         ctx->status = OSSL_CMP_PKISTATUS_unspecified; /* transaction closed */
+        if (srv_ctx->reset_transaction != NULL)
+            (void)srv_ctx->reset_transaction(srv_ctx);
 
     default: /* not closing transaction in other cases */
         break;
diff --git a/crypto/cmp/cmp_vfy.c b/crypto/cmp/cmp_vfy.c
index 1869fae696..8d4de1017d 100644
--- a/crypto/cmp/cmp_vfy.c
+++ b/crypto/cmp/cmp_vfy.c
@@ -786,10 +786,27 @@ int ossl_cmp_msg_check_update(OSSL_CMP_CTX *ctx, const OSSL_CMP_MSG *msg,
                                       CMP_R_TRANSACTIONID_UNMATCHED))
         return 0;
 
+    /*
+     * enable clearing irrelevant errors in attempts to validate recipient nonce
+     * in case of delayed delivery.
+     */
+    (void)ERR_set_mark();
     /* compare received nonce with the one we sent */
     if (!check_transactionID_or_nonce(ctx->senderNonce, hdr->recipNonce,
-                                      CMP_R_RECIPNONCE_UNMATCHED))
-        return 0;
+                                      CMP_R_RECIPNONCE_UNMATCHED)) {
+        /* check if we are polling and received final response */
+        if (ctx->first_senderNonce == NULL
+            || OSSL_CMP_MSG_get_bodytype(msg) == OSSL_CMP_PKIBODY_POLLREP
+            /* compare received nonce with our sender nonce at poll start */
+            || !check_transactionID_or_nonce(ctx->first_senderNonce,
+                                             hdr->recipNonce,
+                                             CMP_R_RECIPNONCE_UNMATCHED)) {
+            (void)ERR_clear_last_mark();
+            return 0;
+        }
+    }
+    /* discard any intermediate error while trying to check recipient nonce */
+    (void)ERR_pop_to_mark();
 
     /* if not yet present, learn transactionID */
     if (ctx->transactionID == NULL
diff --git a/doc/man3/OSSL_CMP_SRV_CTX_new.pod b/doc/man3/OSSL_CMP_SRV_CTX_new.pod
index d7f1a2e4db..fada992e3d 100644
--- a/doc/man3/OSSL_CMP_SRV_CTX_new.pod
+++ b/doc/man3/OSSL_CMP_SRV_CTX_new.pod
@@ -12,7 +12,10 @@ OSSL_CMP_SRV_certConf_cb_t,
 OSSL_CMP_SRV_genm_cb_t,
 OSSL_CMP_SRV_error_cb_t,
 OSSL_CMP_SRV_pollReq_cb_t,
+OSSL_CMP_SRV_reset_transaction_cb_t,
+OSSL_CMP_SRV_delayed_delivery_cb_t,
 OSSL_CMP_SRV_CTX_init,
+OSSL_CMP_SRV_CTX_setup_polling,
 OSSL_CMP_SRV_CTX_get0_cmp_ctx,
 OSSL_CMP_SRV_CTX_get0_custom_ctx,
 OSSL_CMP_SRV_CTX_set_send_unprotected_errors,
@@ -64,6 +67,9 @@ OSSL_CMP_SRV_CTX_set_grant_implicit_confirm
                                           int certReqId,
                                           OSSL_CMP_MSG **certReq,
                                           int64_t *check_after);
+ typedef int (*OSSL_CMP_SRV_reset_transaction_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx);
+ typedef int (*OSSL_CMP_SRV_delayed_delivery_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx,
+                                                  const OSSL_CMP_MSG *req);
  int OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX *srv_ctx, void *custom_ctx,
                            OSSL_CMP_SRV_cert_request_cb_t process_cert_request,
                            OSSL_CMP_SRV_rr_cb_t process_rr,
@@ -71,6 +77,9 @@ OSSL_CMP_SRV_CTX_set_grant_implicit_confirm
                            OSSL_CMP_SRV_error_cb_t process_error,
                            OSSL_CMP_SRV_certConf_cb_t process_certConf,
                            OSSL_CMP_SRV_pollReq_cb_t process_pollReq);
+ int OSSL_CMP_SRV_CTX_setup_polling(OSSL_CMP_SRV_CTX *srv_ctx,
+                                    OSSL_CMP_SRV_reset_transaction_cb_t reset_transaction,
+                                    OSSL_CMP_SRV_delayed_delivery_cb_t delayed_delivery);
 
  OSSL_CMP_CTX *OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX *srv_ctx);
  void *OSSL_CMP_SRV_CTX_get0_custom_ctx(const OSSL_CMP_SRV_CTX *srv_ctx);
@@ -113,6 +122,9 @@ All arguments except I<srv_ctx> may be NULL.
 If a callback for some message type is not given this means that the respective
 type of CMP message is not supported by the server.
 
+OSSL_CMP_SRV_CTX_setup_polling() sets in the given I<srv_ctx> callback functions
+for reseting transaction and intitiating delayed delivery.
+
 OSSL_CMP_SRV_CTX_get0_cmp_ctx() returns the B<OSSL_CMP_CTX> from the I<srv_ctx>.
 
 OSSL_CMP_SRV_CTX_get0_custom_ctx() returns the custom server context from
diff --git a/fuzz/cmp.c b/fuzz/cmp.c
index 490c4211f8..37b6c310c3 100644
--- a/fuzz/cmp.c
+++ b/fuzz/cmp.c
@@ -155,6 +155,17 @@ static int process_pollReq(OSSL_CMP_SRV_CTX *srv_ctx,
     return 0;
 }
 
+static int reset_transaction(OSSL_CMP_SRV_CTX *srv_ctx)
+{
+    return 1;
+}
+
+static int delayed_delivery(OSSL_CMP_SRV_CTX *srv_ctx,
+                                        const OSSL_CMP_MSG *req)
+{
+    return 0;
+}
+
 int FuzzerTestOneInput(const uint8_t *buf, size_t len)
 {
     OSSL_CMP_MSG *msg;
@@ -183,7 +194,9 @@ int FuzzerTestOneInput(const uint8_t *buf, size_t len)
                                        print_noop)
             && OSSL_CMP_SRV_CTX_init(srv_ctx, NULL, process_cert_request,
                                      process_rr, process_genm, process_error,
-                                     process_certConf, process_pollReq))
+                                     process_certConf, process_pollReq)
+            && OSSL_CMP_SRV_CTX_setup_polling(srv_ctx, reset_transaction,
+                                              delayed_delivery))
             OSSL_CMP_MSG_free(OSSL_CMP_SRV_process_request(srv_ctx, msg));
 
         OSSL_CMP_CTX_free(client_ctx);
diff --git a/include/openssl/cmp.h.in b/include/openssl/cmp.h.in
index fa4fe000ba..2e92510446 100644
--- a/include/openssl/cmp.h.in
+++ b/include/openssl/cmp.h.in
@@ -469,6 +469,9 @@ typedef int (*OSSL_CMP_SRV_pollReq_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx,
                                          const OSSL_CMP_MSG *req, int certReqId,
                                          OSSL_CMP_MSG **certReq,
                                          int64_t *check_after);
+typedef int (*OSSL_CMP_SRV_reset_transaction_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx);
+typedef int (*OSSL_CMP_SRV_delayed_delivery_cb_t)(OSSL_CMP_SRV_CTX *srv_ctx,
+                                                  const OSSL_CMP_MSG *req);
 int OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX *srv_ctx, void *custom_ctx,
                           OSSL_CMP_SRV_cert_request_cb_t process_cert_request,
                           OSSL_CMP_SRV_rr_cb_t process_rr,
@@ -476,6 +479,9 @@ int OSSL_CMP_SRV_CTX_init(OSSL_CMP_SRV_CTX *srv_ctx, void *custom_ctx,
                           OSSL_CMP_SRV_error_cb_t process_error,
                           OSSL_CMP_SRV_certConf_cb_t process_certConf,
                           OSSL_CMP_SRV_pollReq_cb_t process_pollReq);
+int OSSL_CMP_SRV_CTX_setup_polling(OSSL_CMP_SRV_CTX *srv_ctx,
+                                   OSSL_CMP_SRV_reset_transaction_cb_t reset_transaction,
+                                   OSSL_CMP_SRV_delayed_delivery_cb_t delayed_delivery);
 OSSL_CMP_CTX *OSSL_CMP_SRV_CTX_get0_cmp_ctx(const OSSL_CMP_SRV_CTX *srv_ctx);
 void *OSSL_CMP_SRV_CTX_get0_custom_ctx(const OSSL_CMP_SRV_CTX *srv_ctx);
 int OSSL_CMP_SRV_CTX_set_send_unprotected_errors(OSSL_CMP_SRV_CTX *srv_ctx,
@@ -492,6 +498,8 @@ X509 *OSSL_CMP_exec_certreq(OSSL_CMP_CTX *ctx, int req_type,
 #  define OSSL_CMP_CR    2
 #  define OSSL_CMP_P10CR 4
 #  define OSSL_CMP_KUR   7
+#  define OSSL_CMP_GENM  21
+#  define OSSL_CMP_ERROR 23
 #  define OSSL_CMP_exec_IR_ses(ctx) \
     OSSL_CMP_exec_certreq(ctx, OSSL_CMP_IR, NULL)
 #  define OSSL_CMP_exec_CR_ses(ctx) \
diff --git a/test/cmp_client_test.c b/test/cmp_client_test.c
index 44c369bc90..ad78c86ec2 100644
--- a/test/cmp_client_test.c
+++ b/test/cmp_client_test.c
@@ -184,7 +184,7 @@ static int test_exec_RR_ses_receive_error(void)
 static int test_exec_IR_ses(void)
 {
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
-    fixture->req_type = OSSL_CMP_IR;
+    fixture->req_type = OSSL_CMP_PKIBODY_IR;
     fixture->expected = OSSL_CMP_PKISTATUS_accepted;
     fixture->caPubs = sk_X509_new_null();
     sk_X509_push(fixture->caPubs, server_cert);
@@ -194,42 +194,55 @@ static int test_exec_IR_ses(void)
     return result;
 }
 
-static int test_exec_IR_ses_poll(int check_after, int poll_count,
-                                 int total_timeout, int expect)
+static int test_exec_any_ses_poll(int req_type, int check_after,
+                                  int poll_count, int total_timeout,
+                                  int expect)
 {
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
-    fixture->req_type = OSSL_CMP_IR;
+    fixture->req_type = req_type;
     fixture->expected = expect;
     ossl_cmp_mock_srv_set_checkAfterTime(fixture->srv_ctx, check_after);
     ossl_cmp_mock_srv_set_pollCount(fixture->srv_ctx, poll_count);
     OSSL_CMP_CTX_set_option(fixture->cmp_ctx,
                             OSSL_CMP_OPT_TOTAL_TIMEOUT, total_timeout);
-    EXECUTE_TEST(execute_exec_certrequest_ses_test, tear_down);
+
+    if (req_type == OSSL_CMP_PKIBODY_IR || req_type == OSSL_CMP_PKIBODY_CR
+        || req_type == OSSL_CMP_PKIBODY_KUR
+        || req_type == OSSL_CMP_PKIBODY_P10CR) {
+        EXECUTE_TEST(execute_exec_certrequest_ses_test, tear_down);
+    } else if (req_type == OSSL_CMP_PKIBODY_GENM) {
+        EXECUTE_TEST(execute_exec_GENM_ses_test, tear_down);
+    } else {
+        result = 0;
+    }
     return result;
 }
 
 static int checkAfter = 1;
 static int test_exec_IR_ses_poll_ok(void)
 {
-    return test_exec_IR_ses_poll(checkAfter, 2, 0, OSSL_CMP_PKISTATUS_accepted);
+    return test_exec_any_ses_poll(OSSL_CMP_PKIBODY_IR, checkAfter, 2, 0,
+                                  OSSL_CMP_PKISTATUS_accepted);
 }
 
 static int test_exec_IR_ses_poll_no_timeout(void)
 {
-    return test_exec_IR_ses_poll(checkAfter, 1 /* pollCount */, checkAfter + 1,
-                                 OSSL_CMP_PKISTATUS_accepted);
+    return test_exec_any_ses_poll(OSSL_CMP_PKIBODY_IR, checkAfter,
+                                  2 /* pollCount */, checkAfter + 4,
+                                  OSSL_CMP_PKISTATUS_accepted);
 }
 
 static int test_exec_IR_ses_poll_total_timeout(void)
 {
-    return test_exec_IR_ses_poll(checkAfter + 1, 2 /* pollCount */, checkAfter,
-                                 OSSL_CMP_PKISTATUS_waiting);
+    return !test_exec_any_ses_poll(OSSL_CMP_PKIBODY_IR, checkAfter + 1,
+                                   3 /* pollCount */, checkAfter + 6,
+                                   OSSL_CMP_PKISTATUS_waiting);
 }
 
 static int test_exec_CR_ses(int implicit_confirm, int granted, int reject)
 {
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
-    fixture->req_type = OSSL_CMP_CR;
+    fixture->req_type = OSSL_CMP_PKIBODY_CR;
     OSSL_CMP_CTX_set_option(fixture->cmp_ctx,
                             OSSL_CMP_OPT_IMPLICIT_CONFIRM, implicit_confirm);
     OSSL_CMP_SRV_CTX_set_grant_implicit_confirm(fixture->srv_ctx, granted);
@@ -256,7 +269,7 @@ static int test_exec_CR_ses_implicit_confirm(void)
 static int test_exec_KUR_ses(int transfer_error, int pubkey, int raverified)
 {
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
-    fixture->req_type = OSSL_CMP_KUR;
+    fixture->req_type = OSSL_CMP_PKIBODY_KUR;
     /* ctx->oldCert has already been set */
 
     if (transfer_error)
@@ -324,7 +337,7 @@ static int test_exec_P10CR_ses(int reject)
     X509_REQ *csr = NULL;
 
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
-    fixture->req_type = OSSL_CMP_P10CR;
+    fixture->req_type = OSSL_CMP_PKIBODY_P10CR;
     fixture->expected = reject ? OSSL_CMP_PKISTATUS_rejection
         : OSSL_CMP_PKISTATUS_accepted;
     ctx = fixture->cmp_ctx;
@@ -354,8 +367,8 @@ static int execute_try_certreq_poll_test(CMP_SES_TEST_FIXTURE *fixture)
 {
     OSSL_CMP_CTX *ctx = fixture->cmp_ctx;
     int check_after;
-    const int CHECK_AFTER = 5;
-    const int TYPE = OSSL_CMP_KUR;
+    const int CHECK_AFTER = 0;
+    const int TYPE = OSSL_CMP_PKIBODY_KUR;
 
     ossl_cmp_mock_srv_set_pollCount(fixture->srv_ctx, 3);
     ossl_cmp_mock_srv_set_checkAfterTime(fixture->srv_ctx, CHECK_AFTER);
@@ -384,7 +397,7 @@ static int execute_try_certreq_poll_abort_test(CMP_SES_TEST_FIXTURE *fixture)
     OSSL_CMP_CTX *ctx = fixture->cmp_ctx;
     int check_after;
     const int CHECK_AFTER = 99;
-    const int TYPE = OSSL_CMP_CR;
+    const int TYPE = OSSL_CMP_PKIBODY_CR;
 
     ossl_cmp_mock_srv_set_pollCount(fixture->srv_ctx, 3);
     ossl_cmp_mock_srv_set_checkAfterTime(fixture->srv_ctx, CHECK_AFTER);
@@ -404,6 +417,26 @@ static int test_try_certreq_poll_abort(void)
     return result;
 }
 
+static int test_exec_GENM_ses_poll_ok(void)
+{
+    return test_exec_any_ses_poll(OSSL_CMP_PKIBODY_GENM, checkAfter, 2, 0,
+                                  OSSL_CMP_PKISTATUS_accepted);
+}
+
+static int test_exec_GENM_ses_poll_no_timeout(void)
+{
+    return test_exec_any_ses_poll(OSSL_CMP_PKIBODY_GENM, checkAfter,
+                                  1 /* pollCount */, checkAfter + 1,
+                                  OSSL_CMP_PKISTATUS_accepted);
+}
+
+static int test_exec_GENM_ses_poll_total_timeout(void)
+{
+    return test_exec_any_ses_poll(OSSL_CMP_PKIBODY_GENM, checkAfter + 1,
+                                  3 /* pollCount */, checkAfter + 2,
+                                  OSSL_CMP_PKISTATUS_waiting);
+}
+
 static int test_exec_GENM_ses(int transfer_error, int total_timeout, int expect)
 {
     SETUP_TEST_FIXTURE(CMP_SES_TEST_FIXTURE, set_up);
@@ -539,6 +572,9 @@ int setup_tests(void)
     ADD_TEST(test_exec_GENM_ses_ok);
     ADD_TEST(test_exec_GENM_ses_transfer_error);
     ADD_TEST(test_exec_GENM_ses_total_timeout);
+    ADD_TEST(test_exec_GENM_ses_poll_ok);
+    ADD_TEST(test_exec_GENM_ses_poll_no_timeout);
+    ADD_TEST(test_exec_GENM_ses_poll_total_timeout);
     ADD_TEST(test_exchange_certConf);
     ADD_TEST(test_exchange_error);
     return 1;
diff --git a/test/cmp_server_test.c b/test/cmp_server_test.c
index e270bb924b..e375ae3d9c 100644
--- a/test/cmp_server_test.c
+++ b/test/cmp_server_test.c
@@ -76,6 +76,7 @@ static int execute_test_handle_request(CMP_SRV_TEST_FIXTURE *fixture)
     if (!TEST_true(OSSL_CMP_SRV_CTX_init(ctx, dummy_custom_ctx,
                                          process_cert_request, NULL, NULL,
                                          NULL, NULL, NULL))
+        || !TEST_true(OSSL_CMP_SRV_CTX_setup_polling(ctx, NULL, NULL))
         || !TEST_ptr(custom_ctx = OSSL_CMP_SRV_CTX_get0_custom_ctx(ctx))
         || !TEST_int_eq(strcmp(custom_ctx, dummy_custom_ctx), 0))
         goto end;
diff --git a/util/libcrypto.num b/util/libcrypto.num
index 0b72559f86..6b7e6c212b 100644
--- a/util/libcrypto.num
+++ b/util/libcrypto.num
@@ -5540,5 +5540,6 @@ OSSL_CMP_CTX_get0_geninfo_ITAVs         ?	3_3_0	EXIST::FUNCTION:CMP
 OSSL_CMP_HDR_get0_geninfo_ITAVs         ?	3_3_0	EXIST::FUNCTION:CMP
 OSSL_CMP_ITAV_new0_certProfile          ?	3_3_0	EXIST::FUNCTION:CMP
 OSSL_CMP_ITAV_get0_certProfile          ?	3_3_0	EXIST::FUNCTION:CMP
+OSSL_CMP_SRV_CTX_setup_polling          ?	3_3_0   EXIST::FUNCTION:CMP
 EVP_DigestSqueeze                       ?	3_3_0	EXIST::FUNCTION:
 ERR_pop                                 ?	3_3_0	EXIST::FUNCTION:
diff --git a/util/other.syms b/util/other.syms
index fa7a59d6a8..bf7eb8b22e 100644
--- a/util/other.syms
+++ b/util/other.syms
@@ -461,6 +461,8 @@ OSSL_CMP_SRV_certConf_cb_t              datatype
 OSSL_CMP_SRV_genm_cb_t                  datatype
 OSSL_CMP_SRV_error_cb_t                 datatype
 OSSL_CMP_SRV_pollReq_cb_t               datatype
+OSSL_CMP_SRV_delayed_delivery_cb_t      datatype
+OSSL_CMP_SRV_clean_transaction_cb_t     datatype
 OSSL_CORE_MAKE_FUNC                     define
 OSSL_PARAM_TYPE                         define
 OSSL_PARAM_octet_ptr                    define