private void UpdateContacts(EntityCollection contacts, Entity contact) { if (contacts == null) { return; } if (contact == null) { return; } ExecuteTransactionRequest multipleRequest = new ExecuteTransactionRequest { Requests = new OrganizationRequestCollection(), ReturnResponses = true }; foreach (Entity existingContact in contacts.Entities) { contact[Attributes.Contact.ContactId] = existingContact.Id; var updateRequest = new UpdateRequest { Target = contact }; multipleRequest.Requests.Add(updateRequest); if (multipleRequest.Requests.Count == 500) { payloadCustomer.Response = CommonXrm.BulkUpdate(multipleRequest, crmService); multipleRequest.Requests.Clear(); } } if (multipleRequest.Requests.Count > 0) { payloadCustomer.Response = CommonXrm.BulkUpdate(multipleRequest, crmService); } }