# sponsorships.invoice.createDraft

Create only a sponsorship invoice draft from an unchanged reviewed previewHash, through the existing invoice engine, source revisions and duplicate/idempotency controls. Unknown tax blocks issuing/sending until explicitly reviewed. Existing invoice issue/send authorization and payment matching remain in force.

`POST /api/v1/accounting/sponsorships.invoice.createDraft`

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

MCP tool: `accounting_sponsorships_invoice_create_draft`

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `id` | string (ID) | Yes | The record's ID. |
| `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. |
| `previewHash` | string | Yes | SHA-256 hash as 64 lowercase hex characters. |
| `additionalInvoiceReason` | string or null |  | Default `null`. |
| `issueDate` | string or null |  | The date the document was issued, as YYYY-MM-DD. |
| `dueDate` | string or null |  | The date payment is due, as YYYY-MM-DD. |
| `taxTreatment` | enum | Yes | One of: `unknown`, `hst`, `gst`, `gst_qst`, `zero_rated`, `exempt`, `none`, `custom`. |
| `taxRateCode` | string or null |  |  |
| `taxReason` | string |  | at most 2000 characters. Default `""`. |
| `terms` | object |  | No other fields. |
| `terms.code` | enum | Yes | One of: `due_on_receipt`, `net_7`, `net_15`, `net_30`, `net_45`, `net_60`, `custom`, `split_50_50`, `monthly`. |
| `terms.days` | integer or null |  |  |
| `priceMinor` | string |  | An amount in cents (the currency's smallest unit), written as a whole-number string such as "1250" for $12.50. Matches ^(?:0\|[1-9]\d{0,18})$. |
| `currency` | string |  | Three-letter currency code, such as CAD or USD. |
| `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/sponsorships.invoice.createDraft \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "id": "9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
  "expectedRevision": 3,
  "previewHash": "9f2b5c1d7e3a4b6c8d0e2f4a6b8c0d2e4f6a8b0c2d4e6f8a0b2c4d6e8f0a2b4c",
  "taxTreatment": "unknown"
}'
```

Reference page: https://app.getoatmilk.com/docs/api/sponsorships.invoice.createDraft