Every plane that flies in American skies needs its own special ID number. Think of it like a license plate for your car, but for airplanes. These numbers are painted right on the plane, usually on the tail, which is why people call them "tail numbers." The requirements for an aircraft registration number follow strict rules set by the government to keep flying safe for everyone.

The United States has more registered aircraft than any other country in the world. That's a lot of tail numbers to keep track of! Each one must be unique, and each one must follow the same basic rules.

If you own a plane or want to buy one, you need to know how these numbers work. The rules might seem confusing at first, but they make sense once you understand the reasons behind them. Let's start by looking at what these tail numbers really are and why they matter so much.

Key Takeaways

An aircraft registration number in the United States must start with the letter "N" and can have up to five more characters (letters or numbers). The FAA requires all planes to display this number in a specific size and location on the aircraft. To register an aircraft, you need to submit an aircraft registration application, pay a $5 fee, and show proof of ownership. The registration lasts seven years and must be renewed to stay current.

RequirementDetails
FormatMust start with "N" + 1 to 5 characters
Characters AllowedNumbers 1-9 and letters (except I and O)
Size on PlaneUsually 12 inches tall (3 inches for some small planes)
LocationTail or fuselage sides between wing and horizontal stabilizer
Registration Cost$5 for new registration or renewal
Duration7 years before renewal needed
Who Can RegisterU.S. citizens, permanent residents, or qualifying companies
Documents NeededApplication form, bill of sale, registration fee

What Is an Aircraft Tail Number?

A tail number is the official name given to every plane. It works like your airplane's personal ID card that everyone can see. You'll find these numbers painted on the outside of the plane, and they help people know exactly which plane is which.

In the United States, every tail number starts with the letter "N." This letter tells you right away that the plane comes from America. After the N, you'll see a mix of numbers and sometimes letters. Here are some examples:

The aircraft can have different types of tail numbers, but they all follow the same basic pattern. Some people call these "N-numbers" because of that letter N at the start. Others call them "registration marks" or just registration numbers.

Where You Can Find Tail Numbers

You can spot tail numbers in a few different places on a plane:

The aircraft must display its number so people can read it from far away. Think about how you can read a billboard from your car. The tail number needs to be that clear. This helps air traffic controllers, other pilots, and anyone on the ground see and identify the plane quickly.

What Makes Each Number Special

No two planes can have the same tail number in the United States. The Federal Aviation Administration keeps track of every single one. When you look up a tail number, you can find out who owns the plane, what kind of plane it is, and other important facts about it.

These numbers stay with planes for a long time, but they can change. If someone sells a plane, the new owner might want a different number. Or maybe someone wants to pick a special number that means something to them, like their initials or a lucky number. The system allows for that, but you have to follow the rules and pay the fees.

Why Do Airplanes Need Registration Numbers?

Registration numbers serve several big jobs in aviation. Each one helps keep flying safe and organized. Here’s a look at why these numbers matter so much.

Safety in the Skies

When a pilot talks on the radio, they use their tail number to identify themselves. Air traffic controllers need to know which plane is which when they're guiding dozens of planes through busy airspace. Imagine trying to direct traffic if all the cars looked exactly the same and had no license plates. It would be chaos!

The registration number makes every conversation clear. A controller might say, "N12345, turn left and climb to 5,000 feet." The pilot knows that message is for them and only them. This clear communication prevents accidents and keeps everyone safe.

Proving Ownership

Just like your car's title proves you own it, an aircraft registration certificate proves who owns a plane. This matters for a lot of reasons:

The registered aircraft has a paper trail that goes back through all its previous owners. This history helps everyone involved in aviation business feel confident about who owns what.

Following the Law

The United States government requires every civil aircraft to have proper registration. This isn't optional. If you try to operate an aircraft without valid registration, you're breaking federal law. The FAA takes this very seriously because unregistered planes create safety risks.

Here's what the law requires:

Tracking and History

Registration numbers help track a plane's entire life story. When mechanics work on a plane, they record the work under that tail number. When inspectors check a plane, they file reports using that number. If a plane is involved in an incident, investigators use the number to look up everything about it.

This tracking system helps everyone in aviation make smart decisions. If you're thinking about buying a used plane, you can look up its registration number and see its complete history. You'll learn if it crashed, if it was rebuilt, or if it has any problems. This information protects buyers and helps them avoid buying planes with hidden issues.

The aircraft registration branch of the FAA maintains all these records in a huge database. Anyone can search this database for free. This openness keeps the system honest and helps aviation stay safe.

How Aircraft Registration Started

The story of aircraft registration goes back over 100 years. Back then, airplanes were brand new, and nobody had figured out how to organize them yet. Countries around the world needed a way to tell planes apart, especially as they started crossing borders.

The Radio Connection

In 1912, countries met in London for the International Radiotelegraphic Conference. They were trying to organize radio signals, not airplanes. But they gave each country special letter codes for radio calls. The United States got the letter "N" for all its radio stations.

When airplanes became more common, countries decided to use these same letters for aircraft registration. It just made sense. The radio codes were already set up, and people were already using them. So in 1919, at a big meeting in Paris, countries officially agreed that aircraft would use these nationality marks.

The United States chose to use its "N" letter for all American planes. This happened officially in 1948, even though some planes used the N earlier. That's why every plane registered in America starts with N to this day.

Why Different Countries Use Different Letters

Each country got its own letter or letters to use. This system helps you know where a plane comes from just by looking at it:

Some countries share letters or need two letters because there aren't enough single letters for every country. But the United States got to keep just "N" all for itself. This works out well because America has so many planes. With more than 330,000 aircraft registered in the United States, we need lots of possible number combinations.

How the Rules Got Organized

After World War II, countries created the International Civil Aviation Organization, or ICAO. This group writes the rules that most countries follow for aviation. They published something called Annex 7, which explains how aircraft nationality and registration marks should work.

The Code of Federal Regulations in the United States follows these international rules but adds more details. You'll find the American rules in 14 CFR Part 47 and Part 45. These sections spell out exactly how to register an aircraft and how to display the numbers.

The rules have changed over the years to make things easier and safer. For example:

The Federal Aviation Administration took over managing registrations in 1958 when it was created. Before that, a different agency called the Civil Aeronautics Administration did the job. But the basic system has stayed the same since 1948.

How to Create a Valid N-Number for Your Aircraft

Creating your registration number means following some specific rules. The good news is that once you know these rules, picking a number becomes pretty straightforward. Let's go over exactly how N-numbers work.

The Basic Format Rules

Every valid N-number follows the same pattern. It always starts with the letter N. After that, you can have up to five more characters. These characters can be numbers, letters, or a mix of both. But you can't just throw any numbers and letters together. Here are the rules you must follow:

Starting Requirements:

Character Rules:

Format Options You Can Choose

The FAA allows several different formats for your N-number. Each one gives you different options for customization:

All Numbers (1 to 5 digits):

Numbers Plus One Letter:

Numbers Plus Two Letters:

Many aircraft owners like to pick numbers that spell something or have personal meaning. You might use your initials, a special date, or a word related to flying. For example, N500FLY or N747JET. Just remember to check if your chosen number is available before you get too attached to it.

Reserved and Restricted Numbers

Some numbers you cannot use because they're set aside for special purposes. The aircraft registration branch keeps these numbers off limits:

Checking If Your Number Is Available

Before you fall in love with a certain N-number, you need to check if it's available. The FAA has an online system where you can search for numbers. Just go to the FAA registry website and look up your desired number. The search will tell you if it's:

The Reservation Process

Once you find an available number you like, you can reserve it. This holds it in your name so nobody else can take it. Here's how it works:

Step 1 - Submit Your Request:

Step 2 - Wait for Confirmation:

Step 3 - Keep Your Reservation Active:

Step 4 - Assign It to Your Plane:

Special Considerations for Historic Numbers

Some older aircraft or replicas can use the old-style format from before 1949. These numbers include a second letter after the N:

To use one of these formats, your aircraft must qualify as an exhibition aircraft, antique aircraft, or be a replica of a plane built at least 30 years ago. The aircraft also needs the right type of airworthiness certificate. These numbers give vintage planes an authentic look, but you still have to follow all the modern registration rules.

Who Can Register an Aircraft in the United States

Not everyone can register an aircraft in the United States. The government has specific rules about who qualifies. These rules exist to make sure American aircraft stay under American control. Let's look at who can and cannot register a plane.

Individual U.S. Citizens

If you're an American citizen, you can register a plane in your own name. This is the simplest way to own an aircraft. You just need to prove your citizenship when you fill out the aircraft registration application. The FAA accepts several forms of proof:

You can also register a plane in multiple names if you're buying it with someone else. For example, a husband and wife might register a plane in both their names. All co-owners must be U.S. citizens.

Permanent Residents

If you're not a U.S. citizen but you have a green card, you can register an aircraft. The official term is "lawfully admitted for permanent residence." You need to show your permanent resident card (green card) when you apply. This proves you have the right to register planes in America even though you're not a citizen.

Partnerships

A partnership can own and register planes, but there's a catch. Every single partner in the partnership must be a U.S. citizen. If even one partner is not American, the whole partnership cannot register the plane. This rule is strict because the government wants to make sure foreign interests don't control American aircraft.

Corporations and Companies

Companies can register an aircraft, but they must meet the requirements for U.S. citizenship. This gets a bit complicated because a company isn't a person. Here's what the FAA requires:

The company must:

Think of it this way: the people who run the company and make decisions must be mostly American. If a foreign company owns too much of an American company, that American company cannot register planes here.

Limited Liability Companies (LLCs)

Many people use LLCs to own aircraft for privacy and liability reasons. An LLC can register an aircraft, and the rules are similar to corporations. All the members who control the LLC must be U.S. citizens or qualifying entities. When you register a plane under an LLC, you need to submit extra paperwork called a "Statement in Support of Registration" that proves the LLC qualifies.

Government Entities

Any U.S. government unit can register planes. This includes:

These organizations don't need to prove citizenship since they're already government entities. However, they do need to show they have the authority to own aircraft.

The Special "Based and Primarily Used" Exception

Here's an interesting exception: a foreign corporation can register an aircraft in the United States under certain conditions. The company must be organized and doing business under U.S. laws, and the aircraft must be "based and primarily used" in America.

"Based and primarily used" means:

This exception helps foreign companies that operate mainly in America. For example, a Canadian company with major U.S. operations might use this rule to register planes here.

Non-Citizen Trusts

Some people who don't qualify to register an aircraft use something called a "non-citizen trust." Here's how it works:

This arrangement is legal and lets people who don't qualify still have control over an aircraft registered in the United States. It's commonly used by foreign individuals or companies that want to operate planes based in America.

What Disqualifies You

Some things will prevent you from registering a plane, even if you otherwise qualify:

Requirements Don't Change Based on Aircraft Type

Whether you're registering a tiny ultralight, a business jet, or unmanned aircraft, the ownership requirements stay the same. The FAA doesn't care what kind of plane it is when deciding who can register it. The rules about citizenship apply equally to all types of civil aircraft.

Where and How to Display Your Tail Number

Once you have your N-number, you need to put it on your plane correctly. The FAA has detailed rules about size, location, and appearance. These rules ensure that anyone can identify the aircraft from a distance. Let's go through each requirement step by step.

Size Requirements for Different Aircraft

The size requirements depend on what type of plane you have. Most planes need big numbers, but some smaller aircraft get to use smaller ones.

Standard Size - 12 Inches:

Most planes need registration marks at least 12 inches tall. This includes:

The 12-inch rule makes sure pilots, controllers, and people on the ground can read your tail number from 500 feet away in daylight. That's about the length of one and a half football fields.

Small Size - 3 Inches:

Some aircraft can use numbers just 3 inches tall:

Very Small Size - 2 Inches:

A few older aircraft get special permission to use even smaller numbers:

Special Rule for Military Zones:

If your plane flies through an Air Defense Identification Zone (ADIZ) or Distant Early Warning Identification Zone (DEWIZ), you must use 12-inch numbers no matter what type of aircraft you have. This rule helps military aircraft and defense systems identify civilian planes quickly.

Location Rules - Where to Put the Numbers

You have two main options for where to place your registration mark on the plane. Both options require the number to show on both sides of the aircraft so people can see it from either direction.

Option 1 - Vertical Tail Surfaces:

You can put the numbers on the tail fin (the vertical surface that sticks up). The numbers must:

Most planes use this option because the tail is easy to see and gives you lots of space for the numbers.

Option 2 - Fuselage Sides:

You can put the numbers on the body of the plane instead. If you choose this option, the numbers must:

Some aircraft have engine pods or other equipment in this area. If these pods are part of the fuselage side, you can put the registration mark on them instead.

What You Cannot Do:

Character Dimensions and Spacing

The rules don't just tell you how tall the numbers should be. They also control the width, thickness, and spacing. This keeps all aircraft numbers looking similar and easy to read.

Width Rules:

Thickness Rules:

Spacing Rules:

Style and Appearance Requirements

Your numbers need to look a certain way to meet the requirements of FAR Part 45, which covers identification and registration marking.

Font Style:

Color and Contrast:

The aircraft displaying its registration must make sure the colors don't blend together. If your plane has a busy paint scheme with lots of colors and patterns, put the numbers on a solid background panel where they'll stand out clearly.

How to Apply the Numbers

The Electronic Code of Federal Regulations in 14 CFR Part 45.21 explains how you must attach the numbers to your plane. They need to be permanent or close to permanent.

Acceptable Methods:

Unacceptable Methods:

The permanent nationality and registration marks need to survive rain, sun, wind, and everything else your plane encounters. When inspectors check your aircraft, they look to make sure your numbers are properly affixed and not coming loose.

Special Display Rules for Certain Aircraft

Some types of aircraft have different rules or exceptions:

Experimental Aircraft:

Amateur-built aircraft must also display the word "EXPERIMENTAL" near each entrance door. This warning must be:

Antique and Exhibition Aircraft:

These aircraft can display permanent nationality and registration marks using the old pre-1949 format like NC, NX, NR, or NL. The second letter doesn't count toward the five-character limit. So NC12345 is legal even though it looks like six characters. The rules for size and placement still apply.

Unmanned Aircraft:

Drones and other unmanned aircraft have slightly different marking rules. The registration number must be:

Small drones under 55 pounds can mark their registration number inside a battery compartment or on a label that's easy to reach.

What Happens If You Don't Follow the Rules

The FAA takes registration mark display rules seriously. If you operate an aircraft with numbers that don't meet the requirements, you're violating federal regulations. This can result in:

Inspectors from the FAA regularly check aircraft at fly-ins, during routine inspections, and at airports. If they spot improper numbers, they'll ask you to correct them. In serious cases, they might prevent you from flying until the numbers are fixed.

Steps to Register Your Aircraft

Registering your plane with the Federal Aviation Administration follows a clear process. Whether you're registering a brand new plane, a used one you just bought, or even unmanned aircraft, the basic steps stay mostly the same. Let's go through the entire aircraft registration process.

Step 1 - Gather Your Documents

Before you start, collect all the paperwork you'll need. Missing documents slow down the process and could delay your registration by weeks or months.

Required Documents:

Aircraft Registration Application (AC Form 8050-1):

Evidence of Ownership:

Special Documents Based on Your Situation:

If you're a corporation or LLC:

If the aircraft was previously registered in another country of registration:

If the aircraft is new:

Step 2 - Fill Out the Application Correctly

The application for registration must be perfect. Small mistakes cause delays. Here's what you need to know:

Owner Information:

Aircraft Information:

Citizenship Documentation:

You must prove you're eligible to register an aircraft:

Registration Number:

You have choices here:

Signatures:

Every person or authorized representative must sign:

Step 3 - Pay the Registration Fee

The fee to register an aircraft is currently $5. This applies whether you're registering for the first time or renewing. Payment methods accepted:

If you're also requesting a custom special registration numbers, add those fees:

Total these amounts and include one payment for everything.

Step 4 - Submit Everything to the FAA

Now send your complete package to the aircraft registration branch:

Mailing Address:

FAA Aircraft Registration Branch, AFS-750
P.O. Box 25504
Oklahoma City, OK 73125

What to Include:

Submission Tips:

Physical Address for Overnight Delivery:

FAA Aircraft Registration Branch
Registry Building, Room 118
6425 South Denning
Oklahoma City, OK 73169-6937

Step 5 - Get Your Temporary Authority

When the FAA receives your application for registration, they'll process it and send you temporary operating authority. This happens while they prepare your permanent certificate of registration.

The Pink Slip:

The second copy of your aircraft registration application becomes your temporary registration. This "pink slip" allows you to operate an aircraft legally while waiting for the permanent certificate. Important points:

Step 6 - Wait for Processing

The FAA handles thousands of registrations every month. Processing times vary:

You can check the status:

Step 7 - Receive Your Permanent Certificate

When processing is complete, the FAA mails your official aircraft registration certificate to the address on your application. This is the real thing:

What the Certificate Includes:

What to Do With It:

The certificate of aircraft registration must be:

Do not keep only a copy in the plane. The FAA requires the original certificate. If you lose it, you can request a replacement, but that takes more time and paperwork.

Special Registration Processes

Some situations need different steps:

Homebuilt Aircraft:

When registering amateur-built aircraft, you need:

Dealer Registrations:

Aircraft dealers use a special certificate that covers multiple planes. If you're a dealer:

Imported Aircraft:

Planes coming from other countries need:

Re-Registration After Expiration:

If your registration expired and you didn't renew in time:

Online Registration Services

The FAA now offers some online services through their CARES (Civil Aviation Registry Electronic Services) system:

Not all registration types can be done online yet, but the system keeps expanding. Check the FAA website for the latest options.

Common Mistakes to Avoid

Even experienced aircraft owners sometimes make mistakes with registration. These errors can delay your certificate, ground your plane, or create legal problems. Let's look at the most common mistakes and how to avoid them.

Documentation Errors

Missing Signatures:

One of the most common problems is unsigned forms. The aircraft registration application requires signatures from all owners. If you're registering a plane with a co-owner, both signatures must be there. Companies need authorized representatives to sign with their title clearly shown.

Check every signature line before mailing:

Incomplete Bill of Sale:

The bill of sale must show a complete chain of ownership. If you bought the plane from someone who wasn't the last registered owner, you need bills of sale for every transfer in between. Missing even one link in the chain causes the FAA to reject your application.

Wrong Legal Names:

Use legal names exactly as they appear on official documents. Don't use:

If your name is "Robert Smith" on your driver's license, don't sign as "Bob Smith." For companies, use the exact name from your articles of incorporation.

Format and Display Mistakes

Wrong N-Number Format:

People often pick N-numbers that break the rules:

Before you get attached to a number, verify it follows all the format rules. Check if it's available before requesting it.

Improper Size:

Using numbers that are too small is a frequent violation. Many aircraft owners paint nice small numbers because they look sleek, but then fail inspection. Remember:

Wrong Location:

Some people put numbers in spots that don't meet the requirements:

Choose a location that follows the rules and makes the registration mark easy to see.

Poor Contrast:

Numbers that don't stand out from the background fail the visibility test. Common contrast problems:

The aircraft displaying registration marks must ensure they're clearly visible from 500 feet away. If you're not sure, take a photo from that distance and see if you can read them.

Application Submission Errors

Missing Documents:

Every application for registration needs complete supporting documents. Don't forget:

Create a checklist and mark off each item as you include it in your package.

Wrong Address:

Using the wrong mailing address causes major delays. Send applications to:

Regular Mail: P.O. Box 25504, Oklahoma City, OK 73125
Overnight: 6425 South Denning, Oklahoma City, OK 73169-6937

Don't send to other FAA offices or addresses. They'll have to forward your package, adding weeks to processing time.

Insufficient Payment:

The basic registration fee is $5, but people often forget to include fees for:

Calculate the total amount needed and include one check for everything.

Timing Mistakes

Flying with Expired Registration:

Some aircraft owners don't realize their registration has expired. You cannot legally operate an aircraft with an expired certificate. Check your expiration date regularly:

Late Renewal:

If you miss the renewal deadline:

Not Updating Address Changes:

When you move, you must tell the aircraft registration branch within 30 days. Failure to do this:

Ownership Change Errors

Operating During Ownership Transfer:

After selling or buying a plane, the new owner needs to register it immediately. The previous certificate of registration becomes invalid when ownership changes. The new owner can operate an aircraft on the pink copy of the application while waiting for the new certificate, but they must have filed that application.

Not Releasing Your Old Number:

If you want to keep your old N-number when you sell your plane, you must reserve it back to yourself during the transfer process. Many sellers forget this step and lose numbers they wanted to keep. The process requires:

This must happen before the plane is sold, or you lose the number forever.

Special Category Mistakes

Missing "EXPERIMENTAL" Placard:

Amateur-built aircraft must display the word "EXPERIMENTAL" near each entrance. This warning is legally required, not optional. It must:

Wrong Historic Format:

Some people think any old plane can use historic format numbers like NC or NX. But this only applies to:

If your plane doesn't qualify, you cannot use the historic format even if you think it looks cool.

Drone Registration Confusion:

People often make mistakes with unmanned aircraft registration:

Keeping Your Registration Current

Getting your aircraft registered is just the beginning. You need to keep that registration valid and up-to-date for as long as you own the plane. Let's talk about what it takes to maintain current registration.

The Seven-Year Renewal Cycle

Your aircraft registration certificate expires seven years after it's issued. This is a big improvement from the old three-year cycle that ended in 2023. Here's how the renewal system works:

When to Renew:

You can file for renewal during the six months before your expiration date. The FAA recommends starting the process at least five months early to make sure your new certificate arrives before the old one expires.

How to Renew:

The Federal Aviation Administration makes renewal easier than initial registration:

Online Renewal:

If nothing has changed since your last registration, you can renew online:

If you've moved, changed your name, or had other changes, you'll need to file a paper renewal form with supporting documents.

Changes That Require Immediate Updates

Some changes mean you need to take action right away, not wait for renewal time. These changes require submitting new registration paperwork:

Change of Ownership:

When you sell your aircraft, the new owner must:

The old certificate becomes invalid the moment ownership changes. The new owner gets temporary authority (the pink slip) while waiting for the permanent certificate.

Change of Address:

You must notify the aircraft registration branch within 30 days of moving. This is mandatory even if your registration isn't close to expiring. You can:

The FAA uses your address to send important notices, including renewal reminders. Wrong address means missed mail and possible problems.

Change of Legal Name:

If you change your legal name (marriage, divorce, court order), you need to update your registration:

Corporate Changes:

Changes to a corporation that owns aircraft require updates:

These changes might affect whether the company still qualifies to register an aircraft in the United States.

Keeping Records and Documents

Smart aircraft owners maintain good records. This makes renewals easier and helps if questions ever come up. Here's what to keep:

Registration Documents:

Ownership Documents:

Address History:

Keep these documents safe. Many owners keep them in the plane along with the current certificate, while storing copies at home or in digital format.

What Happens If Registration Expires

If you miss your renewal deadline, your certificate of aircraft registration becomes invalid. This creates serious problems:

Immediate Consequences:

The N-Number Cancellation Process:

About 90 days after your registration expires, the FAA cancels your N-number assignment. Once cancelled:

Re-Registration:

If your registration expired, you cannot just renew. You must go through the complete registration process again:

This process takes much longer than a simple renewal and costs the same amount. Plus, you cannot fly your aircraft during the entire process unless you have temporary authority.

Setting Up Renewal Reminders

Don't rely on the FAA to remind you. While they do send notices, mail gets lost and people move. Take charge of tracking your own renewal dates:

Mark Your Calendar:

Check Your Certificate:

Annual Check:

Monitoring Your Registration Status Online

The FAA maintains a searchable database of all aircraft registered in the United States. You can check your plane's registration status anytime:

How to Check:

This free service lets you catch problems early. If you notice any errors in the database, contact the aircraft registration branch right away to get them corrected.

Special Situations That Affect Registration

Some circumstances can impact your registration status even if you haven't let it expire:

Aircraft Damage or Destruction:

If your aircraft is substantially damaged or destroyed:

Long-Term Storage:

Even if your plane sits in a hangar for years without flying, you still must maintain current registration. The certificate doesn't have a "not currently flying" exception.

Change in Citizenship:

If the registered owner loses U.S. citizenship or a corporation no longer meets the ownership requirements, the registration becomes invalid immediately. This doesn't wait for expiration - it happens the moment the owner no longer qualifies.

Drug Violations:

If the owner knowingly allowed the aircraft to be used in certain drug crimes, they lose the right to register an aircraft for five years. This applies even if they still own the plane.

Special Cases and Exceptions

Not every aircraft fits the standard registration rules. The FAA has special provisions for unusual situations and specific types of planes. Understanding these exceptions helps if your situation doesn't match the typical case.

Historic and Antique Aircraft

Antique aircraft get some special treatment when it comes to registration and display rules. These are planes with significant age or historic value.

Qualification Requirements:

To use special antique aircraft rules, your plane must:

Special Display Privileges:

Aircraft displaying historic registration can use the old format from before 1949:

For example, an antique aircraft could display NC12345 instead of just N12345. The C doesn't count against the five-character limit, and it gives the plane an authentic vintage look.

Reduced Size Requirements:

Some older aircraft can use registration marks as small as 2 inches tall instead of the standard 12 inches. This exception applies to:

Experimental and Amateur-Built Aircraft

Amateur-built aircraft follow most standard rules, but with