diff --git a/server/AyaNova/Controllers/WorkOrderController.cs b/server/AyaNova/Controllers/WorkOrderController.cs
index efb4dd0c..cf8cbdec 100644
--- a/server/AyaNova/Controllers/WorkOrderController.cs
+++ b/server/AyaNova/Controllers/WorkOrderController.cs
@@ -176,11 +176,12 @@ namespace AyaNova.Api.Controllers
         /// Change existing work order's Contract
         /// applies new Contract and returns complete updated work order
         /// </summary>
+        /// <param name="workOrderId">Work order id</param>
         /// <param name="newContractId">new contract id</param>
         /// <param name="apiVersion">From route path</param>
         /// <returns>WorkOrder</returns>
-        [HttpPost("contract")]
-        public async Task<IActionResult> ChangeContract([FromBody] long? newContractId, ApiVersion apiVersion)
+        [HttpPost("contract/{workOrderId}")]
+        public async Task<IActionResult> ChangeContract([FromRoute] long workOrderId, [FromBody] long? newContractId, ApiVersion apiVersion)
         {
             if (!serverState.IsOpen)
                 return StatusCode(503, new ApiErrorResponse(serverState.ApiErrorCode, null, serverState.Reason));
@@ -189,7 +190,7 @@ namespace AyaNova.Api.Controllers
                 return StatusCode(403, new ApiNotAuthorizedResponse());
             if (!ModelState.IsValid)
                 return BadRequest(new ApiErrorResponse(ModelState));
-            WorkOrder o = await biz.ChangeContract(newContractId);
+            WorkOrder o = await biz.ChangeContract(workOrderId, newContractId);
             if (o == null)
                 return BadRequest(new ApiErrorResponse(biz.Errors));
             else
diff --git a/server/AyaNova/biz/WorkOrderBiz.cs b/server/AyaNova/biz/WorkOrderBiz.cs
index 1245a3a6..cbe77ef1 100644
--- a/server/AyaNova/biz/WorkOrderBiz.cs
+++ b/server/AyaNova/biz/WorkOrderBiz.cs
@@ -314,7 +314,31 @@ namespace AyaNova.Biz
         }
 
 
+        ////////////////////////////////////////////////////////////////////////////////////////////////
+        //CONTRACT UPDATE
+        //       
+        internal async Task<WorkOrder> ChangeContract(long workOrderId, long? newContractId)
+        {
+            //this is called by UI via contract change route for contract change only and expects wo back to update client ui
+            var w=await WorkOrderGetAsync(workOrderId,false,false);
 
+            if (w==null)
+            {
+                AddError(ApiErrorCode.NOT_FOUND, "id");
+                return null;
+            }
+            if(newContractId!=null && !await ct.Contract.AnyAsync(z=>z.Id==newContractId)){
+                AddError(ApiErrorCode.NOT_FOUND,"generalerror", $"Contract with id {newContractId} not found");
+                return null;
+            }
+            w.ContractId=newContractId;
+            await ct.SaveChangesAsync();
+            await EventLogProcessor.LogEventToDatabaseAsync(new Event(UserId, workOrderId, BizType, AyaEvent.Modified), ct);
+            await GetCurrentContractFromContractIdAsync(newContractId);
+            var updatedWorkOrder = await ProcessChangeOfContractAsync(workOrderId);
+            await WorkOrderPopulateVizFields(updatedWorkOrder);
+            return updatedWorkOrder;//return entire workorder
+        }
 
 
         ////////////////////////////////////////////////////////////////////////////////////////////////