How to read an aircraft tail number
The registration painted on an aircraft — its tail number — is a license plate, a birth certificate, and a biography key all at once. Learn to read it and every aircraft you see becomes traceable: who owns it, where it's registered, how old it is, and what's happened to it.
The encoding is simpler than it looks. A tail number is a country prefix plus a unique identifier, and the prefix alone tells you where the aircraft calls home before you've looked anything up.
The country prefix
Every civil registration starts with a prefix assigned by international agreement. Spot the prefix and you know the country of registry instantly:
- N — United States (hence "N-number")
- C-F / C-G — Canada
- G- — United Kingdom
- D- — Germany
- F- — France
- JA — Japan
- VH- — Australia
- XA/XB/XC — Mexico
- B- — China and Taiwan
- HB- — Switzerland
US N-numbers, decoded
A US registration is the letter N followed by one to five characters: up to five digits (N12345), up to four digits plus one letter (N1234A), or up to three digits plus two letters (N123AB). The letters I and O are never used — they read as 1 and 0 from a distance.
Owners can pay for custom ("vanity") N-numbers, which is why you'll see corporate initials and clever combinations on business jets. Short, low-digit N-numbers are prized and often decades old, handed from airframe to airframe — which is itself a story a registry lookup can reveal.
What the registration unlocks
The tail number is your key into the public record. A registry lookup on an N-number returns the aircraft's manufacturer, model, serial number, year, registered owner, and registration status — and cross-referencing it against NTSB records surfaces any accident or incident history riding with the airframe.
In SpotterLog you do this by accident, in the best way: photograph an aircraft, type the tail number you captured, and the app pulls the entire record and attaches it to your sighting. Reading tail numbers stops being an academic skill and becomes the reflex that builds your collection.
Military tail codes are a different system
Military aircraft don't carry civil registrations. US military tails typically show a serial number tied to the fiscal year the airframe was ordered, plus unit codes — the two-letter tail codes on fighter jets identify the wing and base. They won't appear in the FAA registry, but the serial plus a photo will identify the exact airframe through published military registers, and your log entry preserves the details either way.
Frequently asked questions
What do the numbers on a plane's tail mean?+
They're the aircraft's registration: a country prefix (N for the US, G- for the UK, and so on) followed by a unique identifier assigned to that airframe. It works like a license plate that's also the key to the aircraft's public records.
Why do American tail numbers start with N?+
International radio callsign agreements in the 1920s assigned the letter N to the United States for aircraft. Every US-registered civil aircraft has carried an N-number since.
Can two planes have the same tail number?+
Not at the same time — a registration identifies exactly one aircraft while it's assigned. But numbers get reused over the years as aircraft are deregistered, so a lookup on an older registration can involve more than one airframe's history. Registration history is exactly the kind of trail SpotterLog's data is built to untangle.
Put it into practice
SpotterLog is free to start — photograph an aircraft, and the app identifies it, logs the sighting, and pulls its registry, owner, and incident history automatically.