---
title: po.update | Doing Work API
description: Change a draft purchase order's supplier, note or lines (lines replace all lines). Owner or office.
url: https://doingwork.work/docs/reference/po-update/
---

# po.update

Change a draft purchase order's supplier, note or lines (lines replace all lines). Owner or office.

|  |  |
|---|---|
| Who | Agents can call this |
| REST | `POST /v1/purchase-orders/update` |
| MCP tool | `po_update` |
| Writes | yes, send an Idempotency-Key |
| Area | [Shop](https://doingwork.work/docs/reference/#shop) |

## When to use it

Change a draft purchase order's supplier, note or lines (lines replace all lines). Owner or office.

## What to tell the owner

Say what you did in plain words and what happens next.

## Input

| Field | Type | Required |
|---|---|---|
| `po_id` | string (uuid) | yes |
| `vendor_id` | string (uuid) | no |
| `note` | string | no |
| `lines` | array | no |
| `lines[].name` | string | yes |
| `lines[].unit` | string | no |
| `lines[].quantity` | number | yes |
| `lines[].unit_cost_minor` | integer | yes |
| `lines[].unit_price_minor` | integer | no |
| `lines[].taxable` | boolean | no |

## Example

```http
POST https://doingwork.work/v1/purchase-orders/update
content-type: application/json
Idempotency-Key: 3f1c...

{
  "po_id": "00000000-0000-4000-8000-000000000000"
}
```

## Output

JSON. The response shape isn't published yet; read the fields you need and ignore the rest. Errors are `{code, message, status}`.

## Errors

| Code | Status | What to do |
|---|---|---|
| `invalid_input`, `invalid_token`, `rate_limited` |  | Can happen on any call. See [errors](https://doingwork.work/docs/errors/). |