# `invalid_length`: a digit count the plan never uses

The number is neither too short nor too long overall, but its length is one the numbering plan does not assign to any number type.

- Appears in: `reason`
- Billing: Free. Invalid numbers never cost a credit.

Some plans assign several lengths, for example eight and ten digits, with nothing in between; a nine-digit number under such a plan can exist under no type. This is almost always a dropped or doubled digit.

**What to do.** Check for a dropped or doubled digit; the valid lengths per country are published in the libphonenumber metadata named in sources.

```json
{
    "valid": false,
    "reason": "invalid_length",
    "e164": null,
    "country": null,
    "risk_score": null
}
```

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