diff --git a/app/src/Lib/Match/MatchService.php b/app/src/Lib/Match/MatchService.php
index cf33fb5eb..3c4d59184 100644
--- a/app/src/Lib/Match/MatchService.php
+++ b/app/src/Lib/Match/MatchService.php
@@ -972,7 +972,59 @@ public function searchReferenceId(string $sor, string $sorid, AttributeManager $
       // We use a psuedo-rule name
       $potentialMatches->add($downgraded['attrs'], $downgraded['rule']);
     }
-    
+
+    // Check for any potential matches which should be dropped due to Invalidate mode
+    if ($potentialMatches->count() > 0) {
+      $results = $potentialMatches->getRawResults();
+
+      // Check if any Attribute Rules in "Invalidate" mode will demote this result.
+      foreach($results as $rowId => $attrs) {
+        // Find the rule that generated this match.
+        $rulename = $potentialMatches->getRuleForResult($rowId);
+
+        foreach($this->mgConfig->potential_rules as $rule) {
+          if($rule->name == $rulename) {
+            // This is the correct rule, check the Rule Attributes. Note there could
+            // be more than one Rule Attribute with Search Type "Invalidate".
+
+            foreach($rule->rule_attributes as $ruleAttribute) {
+              if($ruleAttribute->search_type == SearchTypeEnum::Invalidate) {
+                // The name of the attribute for this Rule Attribute, eg "dob".
+                // This is the column name, not the API name.
+                $ruleAttributeName = $ruleAttribute->attribute->name;
+
+                // The value in the search request
+                $searchValue = $attributes->getValueByAttribute($ruleAttribute->attribute);
+                // The value in the matched row
+                $rowValue = $results[$rowId][$ruleAttributeName];
+
+                // We only perform the validation check if both values are not empty.
+                if(!empty($searchValue)
+                   && !empty($rowValue)
+                   && ($searchValue !== $rowValue)) {
+                  // The returned value does not match, invalidate the request and drop to no match
+                  // by removing the result from the potential match results
+                  Log::write('debug', $sor . "/" . $sorid . " Invalidate mode for $ruleAttributeName ($rulename) removing result ". $rowId . "\t" . $results[$rowId]['sorid']);
+
+                  // remove the result from potentialMatches ResultManager object
+                  $found = $potentialMatches->remove($rowId);
+                  if (!$found) {
+                    Log::write('warning', $sor . "/" . $sorid . " Invalidate mode - error occurred removing result from potential match result set ". $rowId . "\t" . $results[$rowId]['sorid']);
+                  }
+
+                  // No need to continue with any loop
+                  break 2;
+                }
+              }
+            }
+
+            // We found the rule we're looking for, no need to continue with the loop
+            break;
+          }
+        }
+      }
+    }
+
     // The calling code generally checks to see if any rules successfully ran,
     // since if there were no valid attributes or rules we treat that as an error.
     // If no potential rules ran, we return the canonicalMatches result instead.
diff --git a/app/src/Lib/Match/ResultManager.php b/app/src/Lib/Match/ResultManager.php
index 313e15ccf..f0467f8f7 100644
--- a/app/src/Lib/Match/ResultManager.php
+++ b/app/src/Lib/Match/ResultManager.php
@@ -106,6 +106,44 @@ public function add(array $attributes, string $rule=null) {
     
     $this->rawResults[$rowId] = $attributes;
   }
+
+  /**
+   * Remove a Matchgrid result.
+   *
+   * @since  COmanage Match v1.3.0
+   * @param  int $rowId Row ID to remove
+   * @return bool True if deleted, false if not found
+   */
+  public function remove(int $rowId): bool {
+    $found = false;
+
+    // Remove from $this->results
+    foreach ($this->results as $referenceId => $sorRow) {
+      if (isset($sorRow[$rowId])) {
+        unset($this->results[$referenceId][$rowId]);
+        // If no more results for this referenceId, remove the referenceId key
+        if (empty($this->results[$referenceId])) {
+          unset($this->results[$referenceId]);
+        }
+        $found = true;
+        break; // Assuming rowId is unique across referenceIds within $this->results structure
+      }
+    }
+
+    // Remove from $this->resultRules
+    if (isset($this->resultRules[$rowId])) {
+      unset($this->resultRules[$rowId]);
+      $found = true; // Mark as found even if only found here (though it should be in results too)
+    }
+
+    // Remove from $this->rawResults
+    if (isset($this->rawResults[$rowId])) {
+      unset($this->rawResults[$rowId]);
+      $found = true; // Mark as found even if only found here
+    }
+
+    return $found;
+  }
   
   /**
    * Obtain the number of results.