Aircraft Tail Numbers: How to Register, Reserve, and Display

Aircraft tail numbers are the alphanumeric identifiers the Federal Aviation Administration assigns to every civil aircraft registered in the United States, always beginning with the letter “N” and painted on the airframe so the plane can be traced to a specific owner and registration record. They function much like a license plate. You get one by filing a registration application and a bill of sale with the FAA Aircraft Registry in Oklahoma City, paying a small fee, and either accepting the next available number or reserving a specific one.

How an N-Number Is Built

The “N” prefix identifies the aircraft’s nationality as United States. After the N, the registration can carry up to five more characters in one of three patterns: one to five digits alone, one to four digits followed by a single letter, or one to three digits followed by two letters.¹

Two letters never appear in the sequence: “I” and “O.” They look too much like the numerals 1 and 0 at a distance or in poor visibility.¹

Who Is Allowed to Register

The FAA limits registration to U.S. citizens, lawful permanent residents, and certain qualifying entities. A U.S. citizen simply certifies citizenship on the application. A resident alien must supply proof of permanent residency and the alien registration number issued by the Department of Homeland Security.²

Corporations face tighter rules. The company must be organized under U.S. or state law, its president and at least two-thirds of its board and managing officers must be U.S. citizens, and at least 75 percent of the voting interest must be owned or controlled by U.S. citizens.³ Partnerships qualify only if every partner is a U.S. citizen. A citizen and a resident alien can co-own an aircraft, but not through a partnership structure.²

Trust arrangements add another layer. Every trustee must be a U.S. citizen or resident alien, and if any beneficiary falls outside those categories, the trustee has to submit an affidavit confirming that those beneficiaries collectively hold no more than 25 percent of the power to influence the trustee’s authority over the aircraft.⁴

Documents You Need to Register

Pull together the airframe details first: manufacturer, exact model designation, and factory serial number. Then complete two FAA forms.

Form 8050-1, the Aircraft Registration Application, captures your legal name, physical address, and citizenship status along with the aircraft data. The name on this form must match the purchaser’s name on the bill of sale exactly.⁵

Form 8050-2, the Aircraft Bill of Sale, is your evidence of ownership. Only the seller signs it; the buyer does not. Signatures may be in ink or digital.⁵ Mismatched names or details across the two forms are one of the most common reasons the FAA returns applications, so verify the paperwork lines up before you send anything.

How to Submit and What It Costs

The traditional route is mailing the completed package to the FAA Aircraft Registration Branch in Oklahoma City.⁶ Include a $5 registration fee by check or money order, made out to the Federal Aviation Administration.³

The FAA has also opened limited online registration. Individual owners can now complete guided applications, upload documents, request N-numbers, pay online, and sign digitally through the Aircraft Registry portal.⁷ The online path doesn’t yet cover every scenario, but for a straightforward individual filing it saves time.

The Pink Slip and What It Doesn’t Cover

When you file the application by mail, you keep the second copy. Pilots call it the “pink slip,” and it grants temporary authority to fly the aircraft within the United States while the FAA processes your paperwork. It does not expire on a fixed number of days. It stays valid until the permanent Certificate of Aircraft Registration arrives or the FAA denies the application.⁸

One outer limit does apply: if 12 months pass after the first application following a transfer of ownership without a certificate being issued, the temporary authority expires.⁸ The pink slip also does not authorize international flight. Under customs regulations, it is not a valid certificate of registration for travel outside the United States.⁹ Cross-border flights have to wait for the permanent certificate.

Reserving a Specific Number

If you want a particular combination rather than whatever the system assigns, you can reserve a “special” N-number online with a credit card for $10.¹⁰ Changing the number already on your aircraft to a reserved special number adds another $10, for $20 total. When the reserved number belongs to someone other than the aircraft’s registered owner, both a transfer of the reservation and the number change are required, also totaling $20.¹¹

Painting the Number on the Aircraft

14 CFR Part 45 spells out how the marks must appear. For fixed-wing airplanes, characters must be at least 12 inches high, placed horizontally on both sides of the fuselage between the trailing edge of the wing and the leading edge of the horizontal stabilizer.¹²¹³ If engine pods or other structures occupy that space, the markings go on those surfaces instead. Rotorcraft typically use the fuselage sides or the horizontal stabilizer.

All marks must be painted on or affixed with similar permanence, use colors that contrast with the background, and carry no ornamentation.¹⁴

Where Smaller Marks Are Allowed

Some categories qualify for 3-inch minimum characters:

Gliders.
Amateur-built and exhibition aircraft, provided maximum cruising speed does not exceed 180 knots.
Balloons, airships, powered parachutes, and weight-shift-control aircraft.

If no authorized surface is large enough for full-size marks, you use the largest practicable size on the biggest available surface. Powered parachutes and weight-shift-control aircraft still have to meet the 3-inch floor.¹³

When Registration Expires

A certificate is good for seven years after the last day of the month it was issued. Owners renew with Form 8050-1B during the six months before expiration.¹⁵

Since January 2023, if your registration expires after that date, the FAA automatically extends it another four years and mails a new certificate with the updated expiration date.¹⁶ While a renewal application is being processed, recent statutory changes let you keep flying as long as you carry documentation showing the renewal was submitted and the aircraft is current on maintenance and inspections.¹⁷

Flying Without a Valid Registration

Under federal law, knowingly flying an aircraft without a valid registration certificate can bring criminal penalties of up to three years in prison plus fines under Title 18. An owner who lets someone else fly the aircraft knowing the registration is missing or revoked faces the same exposure.¹⁸

If the flight involves transporting controlled substances, the maximum prison term rises to five years, served consecutively with any other sentence, and the aircraft itself can be seized and forfeited.¹⁸ The FAA can also revoke registration for five years after a controlled substance conviction, with limited exceptions.¹⁷

1
Federal Aviation Administration. Forming an N-Number
2
eCFR. 14 CFR 47.7 – United States Citizens and Resident Aliens
3
Federal Aviation Administration. Aircraft Registration
4
eCFR. 14 CFN 47.7 – United States Citizens and Resident Aliens
5
Federal Aviation Administration. AC Form 8050-2 – Aircraft Bill of Sale
6
Federal Aviation Administration. Contact the Aircraft Registration Branch
7
Federal Aviation Administration. Aircraft Registration
8
eCFR. 14 CFR 47.31 – Temporary Certificate
9
eCFR. 19 CFR Part 122 – Air Commerce Regulations
10
Federal Aviation Administration. Aircraft N-Number Reservation
11
Federal Aviation Administration. Special N-Numbers, Changing N-Numbers
12
eCFR. 14 CFR 45.25 – Location of Marks
13
eCFR. 14 CFR 45.29 – Size of Marks
14
eCFR. 14 CFR Part 45 – Identification and Registration Marking
15
eCFR. 14 CFR 47.40 – Registration Expiration and Renewal
16
Federal Aviation Administration. Aircraft Registration Renewal
17
Office of the Law Revision Counsel. 49 USC 44103 – Registration Requirements
18
Office of the Law Revision Counsel. 49 USC 46306 – Registration Violations Involving Aircraft Not Providing Air Transportation