An aircraft registration number is a unique identifier painted on the outside of a plane that tells you who owns it and where it's registered

Every aircraft has a registration number, also called a tail number or N-number (in the United States). It works like a license plate for a car — it's assigned by the government aviation authority and stays with that specific plane. In the U.S., the Federal Aviation Administration (FAA) issues these numbers. Other countries have their own aviation authorities that do the same thing.

The registration number is painted on the tail fin and fuselage (the body) of the plane so it's visible from the ground and from other aircraft. When you look at a plane, you can read this number and know exactly which aircraft it is, who owns it, and where it's registered. This matters for safety, legal ownership, and tracking.

Key Takeaways

  • U.S. aircraft registration numbers start with the letter N followed by up to five characters (numbers and letters), such as N12345 or N1AB.
  • The FAA assigns registration numbers and keeps a public database where you can look up any plane's owner, history, and current status.
  • Registration numbers are required by law and must be visible on the aircraft at all times during flight.
  • You can search for a plane's registration information on the FAA's online database using the tail number.

How U.S. Aircraft Registration Numbers Are Formatted

In the United States, every registration number begins with the letter N. This letter identifies the plane as registered in the U.S. Other countries use different starting letters — for example, planes registered in Canada start with C, the United Kingdom with G, and Germany with D.

After the N, the number contains up to five more characters. These can be numbers, letters, or a combination. Common formats include N12345 (letter plus four numbers), N1AB (letter plus two numbers plus two letters), or N123AB (letter plus three numbers plus two letters). The FAA assigns these combinations to avoid duplication — no two aircraft in the U.S. registry can have the same N-number.

Why Aircraft Need Registration Numbers

Registration numbers serve several critical purposes. First, they establish legal ownership. When you register an aircraft with the FAA, you receive a Certificate of Aircraft Registration that proves you own that specific plane. The registration number ties the plane to that certificate.

Second, registration numbers are required for safety and air traffic control. When a plane is in the air, air traffic controllers use the registration number to track it on radar and communicate with the pilot. If there's an accident or incident, investigators use the registration number to identify the aircraft and pull its maintenance records and history.

Third, registration numbers allow the public and authorities to verify ownership and check a plane's status. If you see a plane and want to know who owns it, you can look up the registration number in the FAA database.

How to Find Aircraft Registration Information

The FAA maintains a public database called the Aircraft Registration Inquiry system, available on the FAA website. You can search by registration number (tail number) and get information about the aircraft, including the owner's name, the aircraft type, the year it was manufactured, and its current registration status.

To search, you visit the FAA's online registry, enter the N-number, and the system returns the details. This information is public record, so anyone can look it up. You don't need special permission or a login. The database is updated regularly as aircraft change owners or their registration status changes.

If you're at an airport or watching planes, you can photograph the tail number and search it later. If you're tracking a specific aircraft for legitimate reasons — such as researching a plane you're thinking about buying — the registration number is your starting point.

What Happens When an Aircraft Changes Ownership

When an aircraft is sold, the registration number stays with the plane, but the owner information in the FAA database is updated. The new owner must file a new Certificate of Aircraft Registration with the FAA within a certain timeframe. Until that's done, the old owner's name may still appear in the database.

If an aircraft is retired, scrapped, or exported to another country, its registration can be cancelled. Once cancelled, that N-number may eventually be reassigned to a different aircraft, though the FAA typically waits before reusing numbers to avoid confusion.

Registration Numbers on Different Types of Aircraft

All aircraft that fly in U.S. airspace and are registered in the U.S. must have an N-number, regardless of size or type. This includes commercial airliners, private planes, helicopters, gliders, and experimental aircraft. The only exceptions are military aircraft, which use a different identification system.

Commercial airlines paint their N-numbers on the tail in large letters so they're straightforward to read. Private planes and smaller aircraft do the same. The size and placement of the number are regulated by the FAA to may support visibility.

How Registration Numbers Differ Internationally

Every country has its own aviation authority and its own registration system. The first letter of an aircraft's registration number indicates its country of origin. A plane registered in France will have an F-number, one in Australia will have a VH-number, and one in Japan will have a JA-number.

The format after the country letter varies by country. Some countries use only numbers, others use letters and numbers, and the total length differs. But the principle is the same everywhere: the registration number uniquely identifies that aircraft and links it to its owner and country of registration.

Frequently Asked Questions

Can I look up who owns a plane using its tail number?

Yes. Go to the FAA's Aircraft Registration Inquiry system on their website, enter the N-number, and you'll see the registered owner's name, the aircraft type, and its registration status. This information is public record.

What does the N in N-number stand for?

The N stands for the United States. Every aircraft registered in the U.S. has an N-number. Other countries use different letters — Canada uses C, the UK uses G, and so on.

Do private planes have registration numbers?

Yes. Every aircraft that flies in U.S. airspace and is registered in the U.S. must have a registration number, whether it's a commercial airliner, a small private plane, or a helicopter. The only exception is military aircraft.

What happens if a plane's registration number is damaged or faded?

The registration number must be visible and legible at all times. If it's damaged or faded, the owner must repaint it. The FAA can ground an aircraft if the number is not clearly visible.

Can I change my aircraft's registration number?

No. The FAA assigns the registration number when you first register the aircraft, and it stays with that plane for its entire life. You cannot request a different number or customize it.