# budgets.accounts.designate

Designate a bank account for operating cash, GST/HST, income tax, accountant fees or another reserve, optionally capping the reserved amount. The account must belong to this company. Requires its purposeRevision as expectedRevision, or zero when no designation exists. Does not move funds, change a Wise account or make a payment.

`POST /api/v1/accounting/budgets.accounts.designate`

Permissions: `accounting:read`, `accounting:write` · Roles: admin, finance · Idempotency key required · Send `expectedRevision`

MCP tool: `accounting_budgets_accounts_designate`

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `accountId` | string (ID) | Yes | The ID of a bank, card or payment account, from accounts.list. |
| `expectedRevision` | integer | Yes | The record's current revision, from the last time you read it. If someone changed the record since, the request is refused with a conflict so you can reload and check before trying again. 0 to 9007199254740991. |
| `purpose` | enum | Yes | One of: `operating`, `gst_hst`, `income_tax`, `accountant`, `other`. |
| `reserveLimitMinor` | string or null | Yes | An amount in cents (the currency's smallest unit), written as a whole-number string such as "1250" for $12.50. |
| `note` | string | Yes | A short note, kept with the record. at most 2000 characters. |
| `idempotencyKey` | string | Yes | Any unique text you generate once per intended change, so a retried request only happens once. Send it as the Idempotency-Key header instead if you prefer; if you send both they must match. 8–200 characters. |

## Example request

```bash
curl https://app.getoatmilk.com/api/v1/accounting/budgets.accounts.designate \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "accountId": "4d5e6f7a-8b9c-4d0e-8f1a-2b3c4d5e6f7a",
  "expectedRevision": 3,
  "purpose": "operating",
  "reserveLimitMinor": "1250",
  "note": "Synthetic example from the docs"
}'
```

Reference page: https://app.getoatmilk.com/docs/api/budgets.accounts.designate