# company.shareholders.taxNumber.reveal

View or copy one shareholder's full encrypted tax number for t2_schedule_50 or t5_slip, with holderId, purpose and use (view or copy). Requires a signed-in administrator or an accountant with separately approved, unexpired tax_numbers access. Each call rechecks membership and grants, and records the holder, purpose and use without the value. General exports and year-end packages remain masked. Not available to API keys, MCP or AI tools.

`POST /api/v1/accounting/company.shareholders.taxNumber.reveal`

Permissions: `accounting:read`, `accounting:write` · Roles: admin

Not available over MCP: Full taxpayer numbers require a signed-in person, a stated filing purpose, and a separately granted accountant permission. The terminal and connected AI apps receive masked readiness only.

## Fields

| Field | Type | Required | Notes |
| --- | --- | --- | --- |
| `holderId` | string | Yes | Matches ^[a-z0-9][a-z0-9-]{7,39}$. |
| `purpose` | enum | Yes | One of: `t2_schedule_50`, `t5_slip`. |
| `use` | enum | Yes | One of: `view`, `copy`. |
| `period` | object |  | The period to cover. No other fields. |
| `period.from` | string | Yes | The first date to include, as YYYY-MM-DD. |
| `period.to` | string | Yes | The last date to include, as YYYY-MM-DD. |
| `period.kind` | enum | Yes | Which kind of record or job this is. One of: `corporate`, `gst_hst`. |

## Example request

```bash
curl https://app.getoatmilk.com/api/v1/accounting/company.shareholders.taxNumber.reveal \
  -H "Authorization: Bearer $OATMILK_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "holderId": "aaaaaaaa",
  "purpose": "t2_schedule_50",
  "use": "view"
}'
```

Reference page: https://app.getoatmilk.com/docs/api/company.shareholders.taxNumber.reveal