Understand your flight

How to look up your plane by its tail number

Every US-registered aircraft carries a registration mark, the "N-number" or tail number, painted on its tail or the side of its body. You can spot it from the gate window and look it up in the public FAA registry to see what plane you're about to board.

4 official sources, listed at the end Checked October 19, 2026
Photo: Ashim D’Silva randomlies, CC0
In this article · 5 sections
  1. What a tail number is
  2. Where to find it on the plane
  3. How to look it up
  4. What the record tells you (and what it doesn't)
  5. Keep reading

What a tail number is

A tail number is an aircraft's registration mark, a bit like a car's licence plate. In the US it's called an N-number, because every US registration starts with the letter N.

The FAA's rules for forming one are simple. After the N there can be no more than five characters:1

  • one to five numbers (N12345), or
  • one to four numbers and a letter (N1234Z), or
  • one to three numbers and two letters (N123AZ).

The letters I and O aren't used, to avoid confusion with one and zero, and an N-number can't begin with zero.1 Registrations N1 to N99 are reserved for the FAA's own use.1

Aircraft registered in other countries use their own prefixes, so a plane with a different first letter isn't on the US register.

Where to find it on the plane

US rules say a fixed-wing aircraft must display its marks either on the vertical tail or on both sides of the body between the back edge of the wing and the front of the horizontal tail.2 On airliners they're large: for fixed-wing aircraft the marks must generally be at least 12 inches high.3 They also have to contrast with the paint behind them and be legible.

The easiest place to read it is from the gate window before boarding. On many airliners you'll find it near the tail or towards the back of the body. Take a photo so you don't have to remember it.

How to look it up

  • The FAA registry. The FAA's free N-Number Inquiry shows the public registration record for any US aircraft: the make and model, the year it was built and the registration status.4
  • SafelyAboard's tail lookup. Type in the N-number to see the same public FAA registry details in plain English, plus any NTSB records for that aircraft, and a link to its aircraft type page. We don't show private individuals' names, and we don't rate or score any airline or aircraft.

What the record tells you (and what it doesn't)

A registry record tells you what the aircraft is: its manufacturer, model and age. It doesn't say anything about how safe a particular flight will be, and neither do we. Age on its own isn't a safety measure, which is why we've written a separate answer on whether an older plane is less safe. Airliners are maintained and inspected on strict schedules whatever their age; see how often planes are inspected.

For many nervous flyers, the value is simply familiarity: knowing it's "an Airbus A320, built in 2015" turns an anonymous metal tube into something you can read about.

Try it now: snap the tail number at the gate, then look it up with the tail lookup. Afterwards, share a calm, plain-English view of your flight with family using Follow a flight.

Keep reading

Quick answers

What is a tail number?

It's an aircraft's registration mark. US-registered aircraft start with N, followed by up to five numbers and letters, such as N12345 or N123AZ.

Where is the tail number on a plane?

On fixed-wing aircraft, US rules require the marks on the vertical tail or on both sides of the body between the back of the wing and the tail. On most airliners they're at least 12 inches high.

How can I find out what plane I'm on?

Read the N-number from the gate window or the jet bridge, then look it up in the FAA registry or with the SafelyAboard tail lookup, which shows the public registry details and any NTSB records.

Why are there no letters I or O in tail numbers?

The FAA doesn't use them, to avoid confusion with the numbers one and zero.

Sources

(4)
  1. FAA, Aircraft Registration: How to Properly Form an N-Number
  2. 14 CFR § 45.25, Location of marks on fixed-wing aircraft
  3. 14 CFR § 45.29, Size of marks
  4. FAA Aircraft Registry, N-Number Inquiry

Facts last checked against these sources: October 19, 2026.