diff --git a/ajax.php b/ajax.php
index bc052352..1841be1c 100644
--- a/ajax.php
+++ b/ajax.php
@@ -153,4 +153,45 @@ if(isset($_POST['client_set_notes'])){
   // Logging
   mysqli_query($mysqli,"INSERT INTO logs SET log_type = 'Client', log_action = 'Modify', log_description = '$session_name modified client notes', log_ip = '$session_ip', log_user_agent = '$session_user_agent', log_created_at = NOW(), log_client_id = $client_id, log_user_id = $session_user_id, company_id = $session_company_id");
 
+}
+
+/*
+ * Collision Detection/Avoidance
+ * Called upon loading a ticket, and every 2 mins thereafter
+ * Is used in conjunction with ticket_query_views to show who is currently viewing a ticket
+ */
+if(isset($_GET['ticket_add_view'])){
+  $ticket_id = intval($_GET['ticket_id']);
+
+  mysqli_query($mysqli, "INSERT INTO ticket_views SET view_ticket_id = '$ticket_id', view_user_id = '$session_user_id', view_timestamp = NOW()");
+}
+
+/*
+ * Collision Detection/Avoidance
+ * Returns formatted text of the agents currently viewing a ticket
+ * Called upon loading a ticket, and every 2 mins thereafter
+ */
+if(isset($_GET['ticket_query_views'])){
+  $ticket_id = intval($_GET['ticket_id']);
+
+  $query = mysqli_query($mysqli, "SELECT user_name FROM ticket_views LEFT JOIN users ON view_user_id = user_id WHERE view_ticket_id = '$ticket_id' AND view_user_id != '$session_user_id' AND view_timestamp > DATE_SUB(NOW(), INTERVAL 2 MINUTE)");
+  while($row = mysqli_fetch_array($query)){
+    $users[] = $row['user_name'];
+  }
+  if(!empty($users)){
+    $users = array_unique($users);
+    if(count($users) > 1){
+      // Multiple viewers
+      $response['message'] = implode(", ", $users) . " are viewing this ticket.";
+    }
+    else{
+      // Single viewer
+      $response['message'] = implode("", $users) . " is viewing this ticket.";
+    }
+  }
+  else{
+    // No viewers
+    $response['message'] = "";
+  }
+  echo json_encode($response);
 }
\ No newline at end of file
diff --git a/cron.php b/cron.php
index 0e73e5c1..48b7d782 100644
--- a/cron.php
+++ b/cron.php
@@ -257,6 +257,9 @@ while($row = mysqli_fetch_array($sql_companies)){
       }
     }
 
+    // Clean-up ticket views table used for collision detection
+    mysqli_query($mysqli, "TRUNCATE TABLE ticket_views");
+
     // PAST DUE INVOICE Notifications
     //$invoiceAlertArray = [$config_invoice_overdue_reminders];
     $invoiceAlertArray = [30,60,90,120,150,180,210,240,270,300,330,360,390,420,450,480,510,540,570,590,620];
diff --git a/db.sql b/db.sql
index a9cac9da..94fe7d77 100644
--- a/db.sql
+++ b/db.sql
@@ -1274,6 +1274,22 @@ CREATE TABLE `ticket_replies` (
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
 /*!40101 SET character_set_client = @saved_cs_client */;
 
+--
+-- Table structure for table `ticket_views`
+--
+
+DROP TABLE IF EXISTS `ticket_views`;
+CREATE TABLE IF NOT EXISTS `ticket_views` (
+  `view_id` int(11) NOT NULL AUTO_INCREMENT,
+  `view_ticket_id` int(11) NOT NULL,
+  `view_user_id` int(11) NOT NULL,
+  `view_timestamp` datetime NOT NULL,
+  PRIMARY KEY (`view_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
+/*!40101 SET character_set_client = @saved_cs_client */;
+
+-- --------------------------------------------------------
+
 --
 -- Table structure for table `tickets`
 --
diff --git a/ticket.php b/ticket.php
index d085e5bd..44288283 100644
--- a/ticket.php
+++ b/ticket.php
@@ -216,7 +216,7 @@ if(isset($_GET['ticket_id'])){
     <!-- Only show ticket reply modal if status is not closed -->
     <?php if($ticket_status != "Closed"){ ?>
     <form class="mb-3" action="post.php" method="post" autocomplete="off">
-      <input type="hidden" name="ticket_id" value="<?php echo $ticket_id; ?>">
+      <input type="hidden" name="ticket_id" id="ticket_id" value="<?php echo $ticket_id; ?>">
       <div class="form-group">
         <textarea class="form-control summernote" name="ticket_reply" required></textarea>
       </div>
@@ -262,6 +262,8 @@ if(isset($_GET['ticket_id'])){
 
       </div>
 
+      <p class="font-weight-light" id="ticket_collision_viewing"></p>
+
     </form>
     <!-- End IF for reply modal -->
     <?php } ?>
@@ -605,59 +607,98 @@ if(isset($_GET['ticket_id'])){
 
 
 <?php
-if($ticket_status !== "Closed"){
-?>
-<!-- Ticket Time Tracking JS -->
-<script type="text/javascript">
-    // Default values
-    var hours = 0;
-    var minutes = 0;
-    var seconds = 0;
-    setInterval(countTime, 1000);
+if($ticket_status !== "Closed"){ ?>
+  <!-- Ticket Time Tracking JS -->
+  <script type="text/javascript">
+      // Default values
+      var hours = 0;
+      var minutes = 0;
+      var seconds = 0;
+      setInterval(countTime, 1000);
 
-    // Counter
-    function countTime()
-    {
-        ++seconds;
-        if(seconds == 60) {
-            seconds = 0;
-            minutes++;
-        }
-        if(minutes == 60) {
-            minutes = 0;
-            hours++;
-        }
+      // Counter
+      function countTime()
+      {
+          ++seconds;
+          if(seconds == 60) {
+              seconds = 0;
+              minutes++;
+          }
+          if(minutes == 60) {
+              minutes = 0;
+              hours++;
+          }
 
-        // Total timeworked
-        var time_worked = pad(hours) + ":" + pad(minutes) + ":" + pad(seconds);
-        document.getElementById("time_worked").value = time_worked;
-    }
+          // Total timeworked
+          var time_worked = pad(hours) + ":" + pad(minutes) + ":" + pad(seconds);
+          document.getElementById("time_worked").value = time_worked;
+      }
 
-    // Allows manually adjusting the timer
-    function setTime()
-    {
-        var time_as_text = document.getElementById("time_worked").value;
-        const time_text_array = time_as_text.split(":");
-        hours = parseInt(time_text_array[0]);
-        minutes = parseInt(time_text_array[1]);
-        seconds = parseInt(time_text_array[2]);
-    }
+      // Allows manually adjusting the timer
+      function setTime()
+      {
+          var time_as_text = document.getElementById("time_worked").value;
+          const time_text_array = time_as_text.split(":");
+          hours = parseInt(time_text_array[0]);
+          minutes = parseInt(time_text_array[1]);
+          seconds = parseInt(time_text_array[2]);
+      }
 
-    // This function "pads" out the values, adding zeros if they are required
-    function pad(val)
-    {
-        var valString = val + "";
-        if(valString.length < 2)
-        {
-            return "0" + valString;
-        }
-        else
-        {
-            return valString;
-        }
-    }
-</script>
+      // This function "pads" out the values, adding zeros if they are required
+      function pad(val)
+      {
+          var valString = val + "";
+          if(valString.length < 2)
+          {
+              return "0" + valString;
+          }
+          else
+          {
+              return valString;
+          }
+      }
+  </script>
 
 <?php } ?>
 
 <?php include("footer.php");
+
+// jQuery is called in footer, so this must be below it
+if($ticket_status !== "Closed"){ ?>
+  <script type="text/javascript">
+
+    // Collision detection
+    // Adds a "view" entry of the current ticket every 2 mins into the database
+    // Updates the currently viewing (ticket_collision_viewing) element with anyone that's looked at this ticket in the last two mins
+    function ticket_collision_detection() {
+
+        // Get the page ticket id
+        var ticket_id = document.getElementById("ticket_id").value;
+
+        //Send a GET request to ajax.php as ajax.php?ticket_add_view=true&ticket_id=NUMBER
+        jQuery.get(
+            "ajax.php",
+            {ticket_add_view: 'true', ticket_id: ticket_id},
+            function(data){
+                // We don't care about a response
+            }
+        );
+
+        //Send a GET request to ajax.php as ajax.php?ticket_query_views=true&ticket_id=NUMBER
+        jQuery.get(
+            "ajax.php",
+            {ticket_query_views: 'true', ticket_id: ticket_id},
+            function(data){
+                //If we get a response from ajax.php, parse it as JSON
+                const ticket_view_data = JSON.parse(data);
+                document.getElementById("ticket_collision_viewing").innerText = ticket_view_data.message;
+            }
+        );
+    }
+    // Call on page load
+    ticket_collision_detection();
+
+    // Run every 2 mins
+    setInterval(ticket_collision_detection, 120*1000);
+  </script>
+<?php } ?>
\ No newline at end of file