Canadian · Validation

FAA N-number format validator.

Check whether a US tail number is written the way federal rules allow. Format only; there is no checksum in an N-number.

The rule: the letter N, then up to five symbols: all digits (N10000), 1 to 4 digits and one suffix letter (N1000A), or 1 to 3 digits and two suffix letters (N100AB). The first symbol is a digit from 1 to 9, and the letters I and O are never used.

Source: 14 CFR 47.15(b), Wikipedia — Aircraft registrationVerified 29 September 2026

Inputs

Result

Enter an N-number and press Check.

How a US N-number is formed

Every aircraft on the US civil register carries a registration mark beginning with N, informally called the N-number or tail number. 14 CFR 47.15(b) sets the shape of the part after the N.

After the N there are at most five symbols.
They may be all digits (N10000), one to four digits and one suffix letter (N1000A), or one to three digits and two suffix letters (N100AB).
The letters I and O are not used.
The first zero must be preceded by a digit 1 to 9, so the first symbol after N is never 0 and never a letter.

Examples: N1, N17SP and N99999 fit the rules; N0123 (leading zero), N12I45 (letter I) and N123ABC (three letters, six symbols) do not.

Sources: 14 CFR 47.15 and Wikipedia, Aircraft registration, which agree. To see whether a mark is actually assigned, use the FAA Registry N-number inquiry.

Format only — not an FAA registry lookup

This tool checks how the mark is written, entirely in your browser. It cannot confirm that the N-number was ever issued, is currently assigned, or belongs to any aircraft or person; use the FAA Registry for that. Nothing you type is transmitted, stored, or logged.