diff --git a/src/main/java/au/org/ala/biocache/dto/UserAssertions.java b/src/main/java/au/org/ala/biocache/dto/UserAssertions.java
index 07890bdd4..8ef22d3d6 100644
--- a/src/main/java/au/org/ala/biocache/dto/UserAssertions.java
+++ b/src/main/java/au/org/ala/biocache/dto/UserAssertions.java
@@ -1,5 +1,7 @@
 package au.org.ala.biocache.dto;
 
+import org.apache.commons.lang3.StringUtils;
+
 import java.util.ArrayList;
 
 public class UserAssertions extends ArrayList<QualityAssertion> {
@@ -19,4 +21,17 @@ public boolean deleteUuid(String uuid) {
 
         return changed;
     }
-}
\ No newline at end of file
+
+    public boolean updateComment(String uuid, String comment) {
+        boolean changed = false;
+        for (int i = 0; i < this.size(); i++) {
+            if (this.get(i).getUuid().equals(uuid) && StringUtils.compare(this.get(i).comment, comment) != 0) {
+                this.get(i).comment = comment;
+                changed = true;
+                break;
+            }
+        }
+
+        return changed;
+    }
+}
diff --git a/src/main/java/au/org/ala/biocache/service/AssertionService.java b/src/main/java/au/org/ala/biocache/service/AssertionService.java
index 1433e7acf..b9bd2cfb3 100644
--- a/src/main/java/au/org/ala/biocache/service/AssertionService.java
+++ b/src/main/java/au/org/ala/biocache/service/AssertionService.java
@@ -115,6 +115,28 @@ public Optional<QualityAssertion> addAssertion(
         return Optional.empty();
     }
 
+    public boolean editAssertion(
+            String recordUuid,
+            String assertionId,
+            String comment
+    ) throws IOException {
+        logger.debug("Editing assertion to: " + recordUuid + ", assertionId: " + assertionId + ", comment: " + comment);
+
+        SolrDocument sd = searchDAO.getOcc(recordUuid);
+        // only when record uuid is valid
+        if (sd != null) {
+            UserAssertions userAssertions = store.get(UserAssertions.class, recordUuid).orElse(new UserAssertions());
+            // if there's any change made
+            if (userAssertions.updateComment(assertionId, comment)) {
+                // Update assertions
+                updateUserAssertions(recordUuid, userAssertions);
+                return true;
+            }
+        }
+
+        return false;
+    }
+
 
     public boolean deleteAssertion(String recordUuid, String assertionUuid) throws IOException {
         SolrDocument sd = searchDAO.getOcc(recordUuid);
diff --git a/src/main/java/au/org/ala/biocache/web/AssertionController.java b/src/main/java/au/org/ala/biocache/web/AssertionController.java
index fd1c1e6be..4793d17a5 100644
--- a/src/main/java/au/org/ala/biocache/web/AssertionController.java
+++ b/src/main/java/au/org/ala/biocache/web/AssertionController.java
@@ -32,6 +32,7 @@
 import io.swagger.v3.oas.annotations.enums.ParameterIn;
 import io.swagger.v3.oas.annotations.security.SecurityRequirement;
 import io.swagger.v3.oas.annotations.tags.Tag;
+import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.http.entity.ContentType;
 import org.apache.log4j.Logger;
@@ -156,10 +157,11 @@ public ResponseEntity addAssertionWithParams(
             @RequestParam(value = "assertionUuid", required = false) String assertionUuid,
             @RequestParam(value = "relatedRecordId", required = false) String relatedRecordId,
             @RequestParam(value = "relatedRecordReason", required = false) String relatedRecordReason,
+            @RequestParam(value = "updateId", required = false) String updateId,
             HttpServletRequest request,
             HttpServletResponse response) throws Exception {
 
-        return addAssertion(recordUuid, code, userId, userDisplayName, comment, userAssertionStatus, assertionUuid, relatedRecordId, relatedRecordReason, request, response);
+        return addAssertion(recordUuid, code, userId, userDisplayName, comment, userAssertionStatus, assertionUuid, relatedRecordId, relatedRecordReason, updateId, request, response);
     }
 
     /**
@@ -243,6 +245,7 @@ public ResponseEntity addAssertion(
        @RequestParam(value = "assertionUuid", required = false) String assertionUuid,
        @RequestParam(value = "relatedRecordId", required = false) String relatedRecordId,
        @RequestParam(value = "relatedRecordReason", required = false) String relatedRecordReason,
+       @RequestParam(value = "updateId", required = false) String updateId,
        HttpServletRequest request,
        HttpServletResponse response) throws Exception {
 
@@ -251,17 +254,26 @@ public ResponseEntity addAssertion(
         }
 
         try {
-            Optional<QualityAssertion> qa = assertionService.addAssertion(
-                    recordUuid, code, comment, userId, userDisplayName,
-                    userAssertionStatus, assertionUuid, relatedRecordId, relatedRecordReason
-            );
-            if (qa.isPresent()) {
-
-                String server = request.getSession().getServletContext().getInitParameter("serverName");
-                return ResponseEntity
-                        .created(new URI(server + "/occurrences/" + recordUuid + "/assertions/" + qa.get().getUuid()))
-                        .contentLength(0)
-                        .build();
+            // if the updateId is provided then we are editing an existing assertion
+            if (StringUtils.isEmpty(updateId)) {
+                // add the assertion
+                Optional<QualityAssertion> qa = assertionService.addAssertion(
+                        recordUuid, code, comment, userId, userDisplayName,
+                        userAssertionStatus, assertionUuid, relatedRecordId, relatedRecordReason
+                );
+                if (qa.isPresent()) {
+
+                    String server = request.getSession().getServletContext().getInitParameter("serverName");
+                    return ResponseEntity
+                            .created(new URI(server + "/occurrences/" + recordUuid + "/assertions/" + qa.get().getUuid()))
+                            .contentLength(0)
+                            .build();
+                }
+            } else {
+                // update the assertion
+                if (assertionService.editAssertion(recordUuid, updateId, comment)) {
+                    return ResponseEntity.ok().contentLength(0).build();
+                }
             }
 
             throw new ResponseStatusException(HttpStatus.BAD_REQUEST);