TSA Rules Made Simple (What Actually Happens at Airport Security)

You are in line at airport security and your heart rate is already climbing.

Is your liquids bag right?

Do you need to take your shoes off?

What about your laptop?

You have been through security before, but the rules seem to change every time, and the agents move so fast you feel like you are holding up the line.

Airport security is predictable once you know the steps. The TSA follows the same process at every U.S. airport.

The variations are minor (some airports have newer scanners that do not require you to remove liquids or laptops), but the core rules have not changed in years.

Know the steps before you get in line. The sections below cover every part of the checkpoint, from ID check to collecting your bags on the other side.

What Happens at the Security Checkpoint (Step by Step)

The sequence at a standard TSA checkpoint is the same everywhere.

Each step takes 30 seconds to a minute.

The entire process takes 5 to 15 minutes depending on how long the line is.

Step 1: Show your ID and boarding pass

A TSA agent at the podium checks your government-issued photo ID (driver’s license, passport, or passport card) and your boarding pass.

The boarding pass can be on your phone or printed.

They will look at the name and photo, compare it to your face, and wave you through.

If your name on the boarding pass does not match your ID exactly (maiden name vs. married name, a middle initial difference), it usually still works.

But TSA recommends that the name on your ticket match your ID to avoid delays.

REAL ID requirement: Starting May 7, 2025, the TSA requires a REAL ID-compliant driver’s license, state ID, or another acceptable form of identification (passport, passport card, military ID) to fly domestically.

If your license does not have a gold star or other REAL ID marker, check with your state’s DMV or bring your passport instead.

Step 2: Place your items in bins

You will reach a conveyor belt with gray plastic bins. Place the following in separate bins:

• Your liquids bag (one quart-sized clear bag with all your liquid containers)
• Your laptop (removed from its case, placed flat in its own bin)
• Your shoes (most airports require you to remove them)
• Your jacket or coat (removed and placed in a bin)
• Your belt, watch, and any metal jewelry (optional but avoids setting off the scanner)
• Your carry-on bag goes directly on the belt, not in a bin

Note: Some airports with newer CT scanners allow you to leave liquids and laptops in your bag.

You will see signs or hear agents announce this.

If you are not sure, take them out. It is never wrong to separate them.

Step 3: Walk through the scanner

You will either walk through a metal detector (the doorframe shape) or a body scanner (the glass booth where you stand with arms raised for 3 seconds).

The body scanner looks for anything on your body that is not you.

It does not see through your clothes in a detailed way.

It shows the agent a generic outline with any flagged areas highlighted.

What might set off the scanner:

• Metal in your pockets (coins, keys, phone)
• Thick clothing seams, rivets, or buttons
• Medical devices (joint replacements, pacemakers, insulin pumps)
• Bobby pins and hair clips in large quantities
• A wallet or tissues left in your pocket

If the scanner flags something, a TSA agent will ask to do a quick pat-down of that specific area.

This is routine and takes about 15 seconds.

Step 4: Collect your items

Your bins and bags come out on the other side of the X-ray machine.

Collect them, put your shoes and belt back on, repack your liquids and laptop, and you are done.

If a bag gets pulled aside for additional screening, a TSA agent will open it, look through it (sometimes using a swab for chemical residue testing), and return it to you.

This adds 2 to 5 minutes.

It is not a sign that you did anything wrong. It happens randomly.

The 3-1-1 Liquid Rule

This is the rule that causes the most confusion, but it is straightforward once you break it down.

3: Each liquid, gel, or aerosol container must be 3.4 ounces (100 ml) or smaller.

1: All containers must fit in 1 quart-sized clear plastic bag (the zip-top sandwich bag size works).

1: Each passenger gets 1 bag.

What counts as a liquid

More things than you expect:

• Shampoo, conditioner, body wash, lotion
• Toothpaste, mouthwash
• Liquid makeup (foundation, mascara)
• Deodorant (gel or spray, but solid deodorant is fine)
• Contact lens solution
• Sunscreen
• Lip gloss
• Hand sanitizer (currently allowed up to 12 oz, but TSA’s temporary exemption has been changing, so check before you fly)

What does not count as a liquid

• Solid deodorant
• Lip balm (solid)
• Powder makeup (eyeshadow, blush, powder foundation)
• Solid shampoo bars
• Pills and solid medications
• Snacks and food (solid food goes through X-ray, but is not liquid)

What is exempt from the 3-1-1 rule

• Prescription medications in reasonable quantities (liquid or solid)
• Baby formula and breast milk (declare to the agent before screening)
• Medically necessary items (insulin, liquid prescriptions, gel ice packs for medical supplies)

Declare exempt items to the TSA agent before placing your bin on the belt.

They may test them separately, but they will not confiscate them.

TSA’s own walkthrough of the 3-1-1 liquids rule:

TSA's 3-1-1 Liquids Rule

For the complete liquids packing guide, see TSA liquid rules for carry-on.

TSA PreCheck: Is It Worth It?

TSA PreCheck is a trusted traveler program that lets you go through a faster, shorter security line.

You keep your shoes on, your laptop stays in your bag, your belt stays on, and you skip the body scanner (you go through the metal detector only).

Cost: $78 for 5 years ($15.60 per year).

The application: you apply online at tsa.gov/precheck, schedule an in-person appointment (10 minutes at an enrollment center), get fingerprinted, and receive your Known Traveler Number (KTN) by email within a few days.

Is it worth it for occasional travelers?

If you fly 2 or more times per year, yes.

At $15.60 per year, a single trip where you skip a 30-minute security line has paid for itself.

The peace of mind alone is worth it for anyone who finds airport security stressful.

If you fly less than once a year, it is still worth considering if security anxiety is a significant source of travel stress for you.

Important note: PreCheck is not guaranteed on every flight.

Airlines decide which flights get PreCheck availability.

It appears on your boarding pass when available. Most domestic flights have it.

What to Do If You Get Additional Screening

Additional screening (also called secondary screening) is when a TSA agent pulls you aside for extra checks after the standard process.

This might include:

• A pat-down of your full body or a specific area
• A bag search where they open and inspect your carry-on
• A swab test for chemical residue on your hands or bag
• Questions about specific items in your bag

Why it happens:

• Random selection (the scanner flags you randomly, not based on suspicion)
• An item in your bag looked unusual on the X-ray
• The body scanner flagged an area
• You are traveling with items that look dense or unusual on X-ray (large electronics, wrapped gifts, food in jars)

How to stay calm:

• It is routine. Thousands of people get additional screening every day.
• It is not personal.
• You can request a private screening in a separate room if you prefer.
• You can ask to be screened by an agent of the same gender.
• You can ask what they are looking for if you are curious.
• The entire process takes 5 to 10 minutes.

Your Rights at Security

According to the TSA’s own guidance, you have the right to:

• Request a private screening at any time
• Request a same-gender officer for pat-downs
• Refuse to go through the body scanner (you will receive a pat-down instead)
• Keep your belongings in view during screening (ask the agent to keep your bins where you can see them)
• File a complaint if you feel you were treated unfairly (TSA Contact Center: 866-289-9673, or through tsa.gov)
• Travel with medically necessary items regardless of the 3-1-1 rule

You are not required to answer questions beyond confirming your identity.

You are not required to open locked bags (though they may require additional screening).

You are always allowed to decline additional screening and leave the airport instead, though you will not be able to board your flight.

Common Things That Are Fine (But Feel Like They Might Not Be)

• Snacks and food: You can bring sandwiches, fruit, granola bars, and most solid food through security. Soups, sauces, and dips count as liquids.
• Water bottles: Empty bottles are fine. Fill them after security at a water fountain.
• Knitting needles: Allowed in carry-on bags.
• Razors: Disposable razors and electric razors are allowed. Straight razors and safety razor blades are not.
• Wrapped gifts: They can be X-rayed, but TSA may unwrap them if they need a closer look. Pack gifts unwrapped and wrap them later.
• Tools under 7 inches: Screwdrivers, wrenches, and pliers under 7 inches are allowed. Larger tools must be checked.

The Washington Post breaks down TSA checkpoint navigation in under 5 minutes:

How to get an A at TSA

TSA also covers how to prepare your carry-on bags before reaching the checkpoint:

AskTSA: Preparing Carry-on Bags for Security Screening

Not sure if your bag fits?

Check it free with our luggage calculator.

For the full size and weight rules by airline, see the airline baggage rules guide.

For the full list of what to take out at security, see what to take out at airport security.