---
title: "ACK (Acknowledgement Response)"
canonical: "https://wiki.patientsknowbest.com/space/api/3364848470/ACK%20(Acknowledgement%20Response)"
format: markdown
---
> Macro (toc)

# Acknowledgement

## Overview

This message is used to indicate whether PKB received your message successfully or not. There is 1 success code (AA) and 2 error codes (AR or AE) that can be returned in MSA-1.1.

AR is used to indicate an error condition that we have checked for, e.g. a mandatory field was not included.

AE is used to indicate an unexpected error occurred.

## Definition

| **Segment** | **Field** | **Opt** | **RP/#** | **Component** | **Description** | **Example** |
| --- | --- | --- | --- | --- | --- | --- |
| **MSH** |  |  |  |  | Message header. This conforms to PKB's <u>[standard definition](https://wiki.hub.patientsknowbest.com/wiki/spaces/api/pages/3365012972)</u>. |  |
| **MSA** |  |  |  |  | Message acknowledgement |  |
|  | MSA-1 | **R** |  |  | Acknowledgement code |  |
|  |  |  |  | MSA-1.1 | Acknowledgement code. AA = accepted, AR = rejected, AE = error | AR |
|  | MSA-2 | **R** |  |  | Message control ID. This will match the message control ID supplied in the inbound message. |  |
|  |  |  |  | MSA-2.1 | Message control ID | 4003ace9-ab29-4a97-a76a-69d45052dbc6 |
|  | MSA-3 | O |  |  | Text message. If there is an error, this will provide further details. |  |
|  |  |  |  | MSA-3.1 | Text message | Parsing or validation error: SCH-1.1 (placer ID) must be provided. You provided [] |

## Examples

PKB will respond with an ACK message; there are three possible acknowledgement codes.

1. AA: Message received successfully

> MSH|^~\&|HL7API|PKB|App|SendingInst|20190201102500+0000||ACK^R01|PKB-20190201102500+0000|P|2.4
> 
> MSA|AA|messageID

  2. AR: Message rejected due to validation errors (detail included)

> MSH|^~\&;|HL7API|PKB|App|SendingInst|20190201112500+0000||ACK^R01|PKB-20190201112500+0000|P|2.4
> 
> MSA|AR|messageID|Parsing or validation error: OBR[1].OBX[2]: No observation timestamp in OBX or OBR

  3. AE: Unexpected error during processing (usually due to a severely malformed message)

> MSH|^~\&;|HL7API|PKB|App|SendingInst|20190201122500+0000||ACK^R01|PKB-20190201122500+0000|P|2.4
> 
> MSA|AE|messageId|Unexpected error while processing: null

# [Error Responses Guide - HL7 Messages](https://wiki.hub.patientsknowbest.com/wiki/spaces/api/pages/3850600457)