Aircraft Registration Validator

Aircraft registration mark: the tail number and its nationality prefix

Every civil aircraft carries a registration mark ("tail number") that starts with a nationality prefix assigned by ICAO under the Chicago Convention. Brazil uses PP, PT, PR and PS — so PT-MUI or PR-XYZ is a Brazilian aircraft, registered in the RAB (Registro Aeronáutico Brasileiro) run by ANAC. This tool reads the prefix and reports the country of registry.

The prefix is the only part with international meaning; the characters after it are the country's own serialisation. Formats differ widely between countries, which is why a single regex won't validate them all.

Reading the prefix

• Brazil: PP-, PT-, PR-, PS- + three letters (PR- is the current allocation block).
• USA: N + up to 5 digits/letters (the "N-number"), no hyphen.
• UK: G- + four letters; Germany D-; France F-; Italy I-.
• Others: JA#### Japan, B-#### China, VH- Australia, C- Canada, CS- Portugal, EC- Spain.

Where it shows up

• Flight tracking: the tail number links an aircraft to its type, owner and history (RAB, FAA registry, flight-tracker sites).
• Maintenance & ownership: airworthiness certificates and bills of sale key off the mark.
• Insurance & leasing: the registration identifies the asset across borders.
• Mock data / testing: validating that a tail number matches a known national pattern.

Common pitfalls

• Prefix is registry, not build: an aircraft made anywhere can register under any country it qualifies for; the mark shows the registry, not the factory.
• Re-registration changes the mark: selling an aircraft abroad gives it a new prefix and number.
• USA is the odd one: the N-number has no hyphen and mixes digits and letters — don't force the XX-YYY shape on it.
• Format ≠ active: matching a national pattern doesn't mean the registration is current; only the registry confirms that.

FAQ

What do Brazil's PP/PT/PR/PS mean? They are the ICAO nationality blocks allocated to Brazil; PR- is the block most used for newer registrations.

Does the mark tell me the aircraft model? No — model and owner come from the registry record, not from the letters of the mark.

Why doesn't one regex fit all countries? Each state defines its own length and letter/digit rules after the prefix; only the nationality prefix is internationally standardised.