# `unknown_identifier`: no register on this server carries the identifier

The identifier is well formed, and the register that would hold it does not have it.

- Appears in: `reason`
- Billing: Free. An identifier no register could answer for never costs a credit.

For a LEI this means it was never issued, or was issued after the copy of the register this server holds. For a company number it means the register has no company under it.

The register behind the answer is named in `sources` with the date of the copy, so you can see how current it is. The Companies House snapshot is republished monthly and can be up to five weeks behind the live register.

**What to do.** Check the identifier against the register itself if the copy here might be too old. A number that has never existed will not appear there either.

```json
{
    "identifier": "5493001KJTIIGC8Y1R99",
    "identifier_type": "lei",
    "found": false,
    "reason": "unknown_identifier",
    "checksum_valid": false
}
```

Reference: https://spaw.co/docs/reasons/unknown_identifier