diff --git a/lib/diameter/gy/message.h b/lib/diameter/gy/message.h
index 2356738f3..5880ca59c 100644
--- a/lib/diameter/gy/message.h
+++ b/lib/diameter/gy/message.h
@@ -40,8 +40,10 @@ extern "C" {
 #define OGS_DIAM_GY_AVP_CODE_CC_REQUEST_TYPE                (416)
 #define OGS_DIAM_GY_AVP_CODE_CC_TIME                        (420)
 #define OGS_DIAM_GY_AVP_CODE_CC_TOTAL_OCTETS                (421)
+#define OGS_DIAM_GY_AVP_CODE_FINAL_UNIT_INDICATION          (430)
 #define OGS_DIAM_GY_AVP_CODE_GRANTED_SERVICE_UNIT           (431)
 #define OGS_DIAM_GY_AVP_CODE_VALIDITY_TIME                  (448)
+#define OGS_DIAM_GY_AVP_CODE_FINAL_UNIT_ACTION              (449)
 #define OGS_DIAM_GY_AVP_CODE_MULTIPLE_SERVICES_CREDIT_CONTROL (456)
 #define OGS_DIAM_GY_AVP_CODE_SUPPORTED_FEATURES             (628)
 #define OGS_DIAM_GY_AVP_CODE_TIME_QUOTA_THRESHOLD           (868)
@@ -155,6 +157,14 @@ typedef struct ogs_diam_gy_service_unit_s {
     uint64_t cc_output_octets;
 } ogs_diam_gy_service_unit_t;
 
+typedef struct gs_diam_gy_final_unit_s {
+    bool cc_final_action_present;
+#define OGS_DIAM_GY_FINAL_UNIT_ACTION_TERMINATE                 0
+#define OGS_DIAM_GY_FINAL_UNIT_ACTION_REDIRECT                  1
+#define OGS_DIAM_GY_FINAL_UNIT_ACTION_REDIRECT_ACCESS           2
+    int32_t cc_final_action;
+} ogs_diam_gy_final_unit_t;
+
 typedef struct ogs_diam_gy_message_s {
 #define OGS_DIAM_GY_CMD_CODE_CREDIT_CONTROL                         272
 #define OGS_DIAM_GY_CMD_RE_AUTH                                     258
@@ -187,6 +197,7 @@ typedef struct ogs_diam_gy_message_s {
             uint32_t time_threshold;
             uint32_t volume_threshold;
             ogs_diam_gy_service_unit_t granted;
+            ogs_diam_gy_final_unit_t final;
             uint32_t result_code;
             uint32_t *err;
         } cca;
diff --git a/src/smf/context.h b/src/smf/context.h
index 06b9535fd..62d0ee559 100644
--- a/src/smf/context.h
+++ b/src/smf/context.h
@@ -357,6 +357,9 @@ typedef struct smf_sess_s {
         uint64_t dl_octets;
         ogs_time_t duration;
         uint32_t reporting_reason; /* OGS_DIAM_GY_REPORTING_REASON_* */
+        /* Whether Gy Final-Unit-Indication was received.
+         * Triggers session release upon Rx of next PFCP Report Req */
+        bool final_unit;
         /* Snapshot of measurement when last report was sent: */
         struct {
             uint64_t ul_octets;
diff --git a/src/smf/gsm-sm.c b/src/smf/gsm-sm.c
index 7ec051e6f..b42ddbd9c 100644
--- a/src/smf/gsm-sm.c
+++ b/src/smf/gsm-sm.c
@@ -727,6 +727,7 @@ void smf_gsm_state_operational(ogs_fsm_t *s, smf_event_t *e)
 
     ogs_pfcp_xact_t *pfcp_xact = NULL;
     ogs_pfcp_message_t *pfcp_message = NULL;
+    uint8_t pfcp_cause;
 
     ogs_diam_gy_message_t *gy_message = NULL;
     uint32_t diam_err;
@@ -838,6 +839,14 @@ void smf_gsm_state_operational(ogs_fsm_t *s, smf_event_t *e)
             OGS_FSM_TRAN(s, smf_gsm_state_epc_session_will_release);
             break;
 
+        case OGS_PFCP_SESSION_REPORT_REQUEST_TYPE:
+            pfcp_cause = smf_n4_handle_session_report_request(sess, pfcp_xact,
+                            &pfcp_message->pfcp_session_report_request);
+            if (pfcp_cause != OGS_PFCP_CAUSE_REQUEST_ACCEPTED) {
+               OGS_FSM_TRAN(s, smf_gsm_state_wait_pfcp_deletion);
+            }
+            break;
+
         default:
             ogs_error("cannot handle PFCP message type[%d]",
                     pfcp_message->h.type);
diff --git a/src/smf/gy-handler.c b/src/smf/gy-handler.c
index 14ef79d86..51c40ab51 100644
--- a/src/smf/gy-handler.c
+++ b/src/smf/gy-handler.c
@@ -164,6 +164,7 @@ uint32_t smf_gy_handle_cca_initial_request(
     /* Configure based on what we received from OCS: */
     urr_update_time(sess, bearer->urr, gy_message);
     urr_update_volume(sess, bearer->urr, gy_message);
+    sess->gy.final_unit = gy_message->cca.final.cc_final_action_present;
 
     /* Associate acconting URR each direction PDR: */
     ogs_pfcp_pdr_associate_urr(bearer->ul_pdr, bearer->urr);
@@ -221,6 +222,7 @@ uint32_t smf_gy_handle_cca_update_request(
 
     urr_update_time(sess, urr, gy_message);
     urr_update_volume(sess, urr, gy_message);
+    sess->gy.final_unit = gy_message->cca.final.cc_final_action_present;
     /* Associate accounting URR each direction PDR: */
     ogs_pfcp_pdr_associate_urr(bearer->ul_pdr, urr);
     ogs_pfcp_pdr_associate_urr(bearer->dl_pdr, urr);
diff --git a/src/smf/gy-path.c b/src/smf/gy-path.c
index 882787b1b..52a2a0225 100644
--- a/src/smf/gy-path.c
+++ b/src/smf/gy-path.c
@@ -48,6 +48,8 @@ static ogs_thread_mutex_t sess_state_mutex;
 
 static int decode_granted_service_unit(
         ogs_diam_gy_service_unit_t *su, struct avp *avpch1, int *perror);
+static int decode_final_unit_indication(
+        ogs_diam_gy_final_unit_t *fu, struct avp *avpch1, int *perror);
 static void smf_gy_cca_cb(void *data, struct msg **msg);
 
 static __inline__ struct sess_state *new_state(os0_t sid)
@@ -1149,6 +1151,11 @@ static void smf_gy_cca_cb(void *data, struct msg **msg)
                 case OGS_DIAM_GY_AVP_CODE_VOLUME_QUOTA_THRESHOLD:
                     gy_message->cca.volume_threshold = hdr->avp_value->u32;
                     break;
+                case OGS_DIAM_GY_AVP_CODE_FINAL_UNIT_INDICATION:
+                    rv = decode_final_unit_indication(
+                            &gy_message->cca.final, avpch1, &error);
+                    ogs_assert(rv == OGS_OK);
+                    break;
                 default:
                     ogs_warn("Not supported(%d)", hdr->avp_code);
                     break;
@@ -1464,3 +1471,42 @@ static int decode_granted_service_unit(
 
     return OGS_OK;
 }
+
+static int decode_final_unit_indication(
+        ogs_diam_gy_final_unit_t *fu, struct avp *avpch1, int *perror)
+{
+    int ret = 0, error = 0;
+    struct avp *avpch2;
+    struct avp_hdr *hdr;
+
+    ogs_assert(fu);
+    ogs_assert(avpch1);
+    memset(fu, 0, sizeof(*fu));
+
+    ret = fd_msg_browse(avpch1, MSG_BRW_FIRST_CHILD, &avpch2, NULL);
+    ogs_assert(ret == 0);
+    while (avpch2) {
+        ret = fd_msg_avp_hdr(avpch2, &hdr);
+        ogs_assert(ret == 0);
+        switch (hdr->avp_code) {
+        case OGS_DIAM_GY_AVP_CODE_FINAL_UNIT_ACTION:
+            fu->cc_final_action_present = true;
+            fu->cc_final_action = hdr->avp_value->i32;
+            break;
+        /* TODO:
+        case OGS_DIAM_GY_AVP_CODE_REDIRECT_SERVER:
+        case OGS_DIAM_GY_AVP_CODE_FILTER_ID:
+        case OGS_DIAM_GY_AVP_CODE_RESTRICTION_FILTER_RULE:
+        */
+        default:
+            ogs_error("Not implemented(%d)", hdr->avp_code);
+            break;
+        }
+        fd_msg_browse(avpch2, MSG_BRW_NEXT, &avpch2, NULL);
+    }
+
+    if (perror)
+        *perror = error;
+
+    return OGS_OK;
+}
diff --git a/src/smf/n4-handler.c b/src/smf/n4-handler.c
index db1f91c2f..ec1a63f9b 100644
--- a/src/smf/n4-handler.c
+++ b/src/smf/n4-handler.c
@@ -1147,7 +1147,9 @@ uint8_t smf_epc_n4_handle_session_deletion_response(
     return OGS_PFCP_CAUSE_REQUEST_ACCEPTED;
 }
 
-void smf_n4_handle_session_report_request(
+/* Returns OGS_PFCP_CAUSE_REQUEST_ACCEPTED on success,
+ * other cause value on failure */
+uint8_t smf_n4_handle_session_report_request(
         smf_sess_t *sess, ogs_pfcp_xact_t *pfcp_xact,
         ogs_pfcp_session_report_request_t *pfcp_req)
 {
@@ -1185,7 +1187,7 @@ void smf_n4_handle_session_report_request(
         ogs_pfcp_send_error_message(pfcp_xact, 0,
                 OGS_PFCP_SESSION_REPORT_RESPONSE_TYPE,
                 cause_value, 0);
-        return;
+        return cause_value;
     }
 
     ogs_assert(sess);
@@ -1225,7 +1227,7 @@ void smf_n4_handle_session_report_request(
                         ogs_pfcp_send_error_message(pfcp_xact, 0,
                                 OGS_PFCP_SESSION_REPORT_RESPONSE_TYPE,
                                 OGS_PFCP_CAUSE_SERVICE_NOT_SUPPORTED, 0);
-                        return;
+                        return OGS_PFCP_CAUSE_SERVICE_NOT_SUPPORTED;
                     }
 
                     if (qfi) {
@@ -1235,7 +1237,7 @@ void smf_n4_handle_session_report_request(
                             ogs_pfcp_send_error_message(pfcp_xact, 0,
                                 OGS_PFCP_SESSION_REPORT_RESPONSE_TYPE,
                                 OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND, 0);
-                            return;
+                            return OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND;
                         }
                     }
                 } else {
@@ -1260,7 +1262,7 @@ void smf_n4_handle_session_report_request(
             ogs_pfcp_send_error_message(pfcp_xact, 0,
                     OGS_PFCP_SESSION_REPORT_RESPONSE_TYPE,
                     OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND, 0);
-            return;
+            return OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND;
         }
 
         switch (sess->up_cnx_state) {
@@ -1332,14 +1334,21 @@ void smf_n4_handle_session_report_request(
             sess->gy.reporting_reason =
                 smf_pfcp_urr_usage_report_trigger2diam_gy_reporting_reason(&rep_trig);
         }
-        switch(smf_use_gy_iface()) {
+        switch (smf_use_gy_iface()) {
         case 1:
-            smf_gy_send_ccr(sess, pfcp_xact,
-                    OGS_DIAM_GY_CC_REQUEST_TYPE_UPDATE_REQUEST);
+            if (!sess->gy.final_unit) {
+                smf_gy_send_ccr(sess, pfcp_xact,
+                        OGS_DIAM_GY_CC_REQUEST_TYPE_UPDATE_REQUEST);
+            } else {
+                ogs_debug("[%s:%s] Rx PFCP report after Gy Final Unit Indication",
+                          smf_ue->imsi_bcd, sess->session.name);
+                /* This effectively triggers session release: */
+                cause_value = OGS_PFCP_CAUSE_NO_RESOURCES_AVAILABLE;
+            }
             break;
         case -1:
             ogs_error("No Gy Diameter Peer");
-            /* TODO: terminate connection */
+            cause_value = OGS_PFCP_CAUSE_NO_RESOURCES_AVAILABLE;
             break;
         /* default: continue below */
         }
@@ -1379,4 +1388,5 @@ void smf_n4_handle_session_report_request(
                     0));
         }
     }
+    return cause_value;
 }
diff --git a/src/smf/n4-handler.h b/src/smf/n4-handler.h
index 76a257d12..b5e89886e 100644
--- a/src/smf/n4-handler.h
+++ b/src/smf/n4-handler.h
@@ -47,7 +47,7 @@ uint8_t smf_epc_n4_handle_session_deletion_response(
         smf_sess_t *sess, ogs_pfcp_xact_t *xact,
         ogs_pfcp_session_deletion_response_t *rsp);
 
-void smf_n4_handle_session_report_request(
+uint8_t smf_n4_handle_session_report_request(
         smf_sess_t *sess, ogs_pfcp_xact_t *pfcp_xact,
         ogs_pfcp_session_report_request_t *pfcp_req);
 
diff --git a/src/smf/pfcp-sm.c b/src/smf/pfcp-sm.c
index bf0235842..2fe69d1f3 100644
--- a/src/smf/pfcp-sm.c
+++ b/src/smf/pfcp-sm.c
@@ -370,8 +370,14 @@ void smf_pfcp_state_associated(ogs_fsm_t *s, smf_event_t *e)
         case OGS_PFCP_SESSION_REPORT_REQUEST_TYPE:
             if (!message->h.seid_presence) ogs_error("No SEID");
 
-            smf_n4_handle_session_report_request(
-                sess, xact, &message->pfcp_session_report_request);
+            if (!sess) {
+                    ogs_error("No Session");
+                    ogs_pfcp_send_error_message(xact, 0,
+                        OGS_PFCP_SESSION_REPORT_RESPONSE_TYPE,
+                        OGS_PFCP_CAUSE_SESSION_CONTEXT_NOT_FOUND, 0);
+                    break;
+            }
+            ogs_fsm_dispatch(&sess->sm, e);
             break;
 
         default: