> ## Documentation Index
> Fetch the complete documentation index at: https://docs.compliapi.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Screen a vessel

> Screen a ship by IMO number or MMSI across the sanctions lists

Screens a ship by its **IMO number** (7 digits) or **MMSI** (9 digits) across every enabled list that publishes ship identifiers — the US OFAC SDN list, the UK Sanctions List, the Swiss SECO list, Canada's and Australia's consolidated lists and the French Trésor register. Use it before chartering, insuring, financing or trading cargo with a vessel, alongside screening the vessel's name with [`/screen/name`](https://docs.compliapi.com/api/screen/name) (`type=vessel`).

**identifier** `string` *required*

An IMO number, with or without the `IMO` prefix (`IMO 9116412`, `IMO9116412` and `9116412` are the same), or an MMSI. Anything else returns `400`.

**lists** `string`

Comma-separated [list slugs](https://docs.compliapi.com/api/screen/lists.md) to screen against (default: all enabled lists).

Matching is exact on the number: each list's own formatting is ignored, and every listed identifier is returned in one canonical form (`IMO 9116412`, `MMSI 422000000`), so the same ship listed by several authorities — often under different spellings of its name — matches on every list that carries it. Each match's `metadata` carries `kind` (`imo` or `mmsi`) and the listed vessel's name; the response is the shared [screening envelope](https://docs.compliapi.com/api/screen.md).

```json Example response theme={null}
{
  "value": "IMO 9116412",
  "flagged": true,
  "sanctioned": true,
  "lists_checked": ["ofac", "ofac_consolidated", "uk_fcdo_sanctions"],
  "matches": [
    {
      "list": "ofac",
      "list_name": "US OFAC SDN",
      "list_type": "sanctions",
      "match": "exact",
      "value": "IMO 9116412",
      "source_url": "https://sanctionssearch.ofac.treas.gov/Details.aspx?id=27304",
      "metadata": { "sdn_name": "ADRIAN DARYA 1", "sdn_type": "Vessel", "kind": "imo" }
    }
  ]
}
```

An IMO number identifies a hull for its whole life, while a ship's name, flag and MMSI can change — screen the IMO number whenever you have it. Company IMO numbers (also 7 digits) are a different register and are not screened here.


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