14 Budget Airline Add-On Fees to Watch Out For Before You Click “Book”

You find a flight for $39. You feel clever. You enter your details, click through a few screens, and by the time you reach the payment page, your “bargain” fare has more than tripled.

That is the budget airline business model. The headline fare gets you to click. The add-ons make the airline its money. Many low-cost carriers earn a large share of their revenue from what the industry calls “ancillary” income: bags, seats, boarding, snacks, and fees most travelers never saw coming.

Budget airlines are not a scam, and flying on them can still save you real money. The trick is knowing exactly where the extra charges hide so you can decide which ones to pay, which to avoid, and when a “cheap” ticket is really the expensive one.

This guide walks through 14 budget airline add-on fees to watch out for before you book. For each one, you’ll learn what the fee is, why it catches people off guard, what it typically costs, and how to reduce or avoid it. Near the end, you’ll find a booking checklist, a method for comparing true total costs, and answers to common questions.

A quick note on prices: Fees vary by airline, route, travel date, and how early you pay, and carriers change them often. The ranges below are typical of what low-cost carriers charge, not guarantees. Always check the airline’s current fee page and the final checkout total before paying.

Key Takeaways

• The advertised fare on a budget airline usually covers one thing: a seat on the plane for you and a small personal item.
• Carry-on bags, checked bags, seat assignments, and airport check-in are the four biggest fee categories, and prices rise the closer you get to departure.
• Paying for extras online at booking is almost always cheaper than paying later, at the airport, or at the gate.
• A full-service carrier can be cheaper than a budget airline once you add the extras you actually need. Compare totals, not base fares.
• Screenshots, a tape measure, a luggage scale, and a no-nonsense checkout routine will save you more than any coupon code.

Why Budget Airlines Charge So Many Fees

Understanding the logic behind the fees makes them easier to spot.

Low-cost carriers (LCCs) compete mostly on the price shown in search results. Because travelers sort by “lowest price,” airlines have a strong incentive to show the smallest possible number. Everything that is not strictly required to move you from A to B gets “unbundled” and sold separately.

This works in the airline’s favor for three reasons.

1. Anchoring. Once you have committed time and effort to a booking, an extra $35 for a bag feels small compared with starting over.

2. Price discrimination. Travelers who need a bag, a specific seat, or flexibility pay more. Travelers who pack light and take what they are given pay less. Airlines argue this is fair, since you only pay for what you use.

3. Timing pressure. Fees often rise at the airport, when you have no alternatives. That is why the same bag can cost $45 online and $99 at the gate.

Knowing this, your strategy is simple: decide what you need before you book, pay for it at the cheapest possible moment, and refuse everything else.

1. Carry-On Bag Fees

Typical cost: $0 to $100+ per leg, depending on airline and when you pay.

This is the fee that surprises the most travelers. On many budget carriers, particularly several in the United States and Europe, your fare includes only a personal item that fits under the seat in front of you. A standard rolling carry-on that goes in the overhead bin costs extra.

Why it catches people

Many travelers assume a carry-on is free because it is on almost every full-service airline. On budget carriers, the personal item allowance is often small, sometimes about the size of a school backpack, and the airline enforces it with measuring frames at the gate.

The pricing is also tiered by time. A carry-on added during booking might cost $30 to $60. Added after booking through “manage my trip,” it is often more. Added at the airport, it can cost $60 to $100 or more, and gate-checking an oversized personal item can trigger the highest rate.

How to avoid or reduce it

• Pack to the personal item size. Check the airline’s exact dimensions, then buy a bag that fits them. Some travelers buy a soft-sided “under-seat” bag designed to match low-cost carrier limits.
• Wear your heaviest items. A jacket with big pockets, a travel vest, and your bulkiest shoes can free up significant space.
• Pre-pay online. If you need the carry-on, add it during booking, not later.
• Check whether a bundle is cheaper. Some airlines bundle a carry-on, seat, and priority boarding at a discount versus buying each separately.
• Measure at home. Take a tape measure to your bag, including wheels and handles. Airlines measure the full outside dimensions.

Pro tip: If you only need a carry-on on one leg of a round trip, check whether the airline charges per direction. Some do, and the fee can differ on each leg.

2. Checked Bag Fees

Typical cost: Roughly $30 to $80 for the first bag online, often $10 to $30 more at the airport, with second bags costing more.

If you cannot fit your trip into a carry-on, you will pay to check a bag. Budget carriers typically charge for every checked bag, including the first.

Why it catches people

Checked bag pricing is dynamic. It depends on:

• When you buy it. Online at booking is cheapest, online after booking is usually a bit higher, and the airport counter is highest.
• The route. Longer or international routes may cost more.
• Weight tier. Some airlines sell bags at a base weight (for example, 15 or 20 kg on many European carriers) and charge more for heavier options.
• Number of bags. The second bag is often priced higher than the first.

Since the cost can double between booking and the airport, procrastinating on this decision is expensive.

How to avoid or reduce it

• Decide at booking. Choose your bag when you purchase your ticket, not later.
• Share a bag. If you are traveling with a partner or family, one larger checked bag split among several people is often cheaper than several smaller bags. Check weight limits first.
• Ship ahead on long stays. For trips of a week or more with bulky items, shipping a box can sometimes beat a per-bag fee.
• Compare with a legacy carrier. A full-service airline that includes one checked bag may cost less overall on bag-heavy trips.
• Check bag and weight rules before packing. Know the maximum weight and dimensions so you do not pay an overweight fee later (see fee #7).

3. Seat Selection Fees

Typical cost: About $5 to $60+ per seat, per flight, with premium or extra-legroom seats costing more.

If you decline to pay for a seat, the airline will usually assign you one at random at check-in. That can mean a middle seat, a seat far from your companions, or a spot at the back of the plane.

Why it catches people

Seat pricing varies by row. A seat in the back might cost a few dollars, while front-row, exit-row, and extra-legroom seats cost much more. Prices can also change based on demand and flight length.

The bigger problem is splitting up groups. If you do not pay for seats, you may be seated apart from your travel partners. That creates pressure to pay for adjacent seats on every leg, which can add up quickly on a family trip.

How to avoid or reduce it

• Skip the fee if you are flying solo and flexible. If you do not mind where you sit, a random assignment costs nothing.
• Pay only for the important flights. On a round trip, you might pay for seats on a long overnight leg and skip them on a short daytime hop.
• Wait for free check-in seat assignment, if offered. Some airlines assign seats at check-in without a fee, though the choice will be limited. Check the airline’s policy before relying on this.
• Use a bundle. If a fare bundle includes seat selection plus a bag, it may cost less than buying each.
• Travel with young children? Look up the airline’s family seating policy. Some carriers state they will try to seat young children with an adult at no charge, but policies differ and are not always guaranteed.

Pro tip: Do not assume a cheap seat price is the lowest you will see. Check again after a few days. Seat fees can fluctuate, and an occasional promotion can drop prices.

4. Airport Check-In and Boarding Pass Printing Fees

Typical cost: Varies widely; on some carriers, $10 to $60 per passenger if you fail to complete online check-in or need a printed pass.

Some low-cost airlines require you to check in online within a set window and charge a penalty if you check in at the airport desk instead. Others charge to print a boarding pass at the airport.

Why it catches people

This fee punishes the unprepared. If your phone dies, your internet is spotty, you forget to check in, or you do not realize the airline requires online check-in, you can be charged at the counter. Travelers who are less comfortable with technology and international travelers without data access are hit hardest.

Airline policies on this are changing. Several carriers have been moving to digital boarding passes and adjusting or removing their desk check-in charges, so the situation varies by airline and over time. Treat this fee as one to verify, not one to assume.

How to avoid or reduce it

• Read the check-in rules when you book. Find the online check-in window and the penalty for missing it.
• Set a reminder. As soon as check-in opens, complete it and save your boarding pass to your phone.
• Download the boarding pass. Save a copy to your phone’s wallet or screenshots so you do not depend on a data connection.
• Keep the airline’s app installed and logged in. Some carriers only provide boarding passes through the app.
• Print at home or your hotel if a paper pass is required. Printing for free beats paying at the airport.

5. Priority Boarding Fees

Typical cost: Roughly $5 to $30 per person, per flight.

Priority boarding lets you board early. On budget airlines, it often comes bundled with a larger carry-on allowance.

Why it catches people

On many low-cost carriers, priority boarding is not just about convenience. It can be the only way to guarantee overhead bin space for a larger carry-on. If the airline sells a “priority” product that includes a bigger bag, skipping it can mean paying more at the gate for the same bag.

But on other airlines, priority boarding is pure convenience. You pay extra to walk onto the plane a few minutes sooner. During the booking flow, it is often presented as a tick-box that is easy to select by accident.

How to avoid or reduce it

• Know what yours includes. Read the fine print. If it only buys earlier boarding, consider skipping it.
• Do not select it by accident. Review each screen before clicking “continue.”
• Board with your group as assigned. If you have no large bag and you are not worried about bin space, boarding later costs you nothing.
• Check bundle value. If priority comes with a bag and seat you need anyway, a bundle can save money.
• Consider whether you want to be first. A short wait to board seldom changes your trip.

6. Payment and “Booking” Fees

Typical cost: Often $5 to $25 per passenger, per flight, or a percentage of the fare when paying by card.

Some airlines add a charge simply for paying. It may be called a “booking fee,” “payment fee,” “processing fee,” “administration fee,” or “convenience fee.”

Why it catches people

These fees often appear late in checkout, after you have chosen your flight, entered passenger details, and selected extras. By then, you are committed. The fee may also apply per passenger and per flight segment, so a round trip for four people can add a surprising amount.

On some carriers, certain payment methods carry a lower fee or none. Debit cards, a particular card brand, or a specific payment platform may be exempt.

How to avoid or reduce it

• Check which payment methods are fee-free. The airline’s payment page or fee table will say.
• Compare payment options before entering details. Switching methods at the final screen can change the total.
• Look at the total before the “pay” button. Make a habit of reading the full price breakdown on the final page.
• Use a card with no foreign transaction fee if you are paying in another currency (see fee #14).
• Watch for “service” charges on phone bookings. Booking by phone, or through a call center, often costs more than online.

7. Overweight and Oversized Baggage Fees

Typical cost: Often $30 to $100+ for an overweight bag, and higher still for oversized bags.

You paid for your bag. You packed it. Then at the airport, the scale reads a kilo or two over the limit, and you are hit with another charge.

Why it catches people

Budget airlines enforce weight limits strictly, and the penalty is usually much higher than the cost of pre-purchasing extra weight online. A bag that is slightly over can trigger a flat fee that is a significant portion of the ticket price.

The same applies to size. A carry-on that does not fit the sizer, or a checked bag that exceeds the dimension limit, can bring a penalty.

Shopping on your trip makes it worse. Souvenirs, bottles, and gifts fill the case on the way home, and the return leg is when most overweight fees happen.

How to avoid or reduce it

• Buy a luggage scale. A small handheld scale is inexpensive and can save you from one costly surprise.
• Pre-buy extra weight online if you need it. Adding weight at booking is typically far cheaper than paying at the airport.
• Repack at the counter, if needed. Move heavy items into your personal item or wear them.
• Plan for the return trip. If you expect to bring things home, leave space or pre-buy additional weight.
• Check size limits. Measure the bag, including wheels and handles, against the airline’s stated dimensions.

Pro tip: Keep your bag a few hundred grams under the limit. Scales at airports are not always identical to yours.

8. Change and Cancellation Fees

Typical cost: Varies widely. Some budget fares charge $50 to $150+ per change, and the cheapest fares may be non-refundable.

Plans change. On a budget airline, changing them can cost more than the original ticket.

Why it catches people

The cheapest fares are often the least flexible. Some carriers allow no changes at all on their lowest fare. Others allow changes but charge a fee plus any fare difference. If the new flight costs more, you pay the gap too.

Cancellation is similar. You may get no refund for the fare, though taxes and airport charges may sometimes be refundable depending on the airline and local rules. Rules vary by country, and regulations can protect you in certain situations, such as when the airline cancels or significantly changes your flight.

In the United States, federal rules require airlines to provide refunds when they cancel a flight or make a significant change, and you choose not to travel. Other regions, including the EU and UK, have their own passenger-rights rules. Check the regulations that apply to your route, and keep in mind that your rights depend on who initiated the change.

How to avoid or reduce it

• Book only when your plans are firm. If you are unsure, a cheap non-refundable fare may be a gamble.
• Compare flexible fares. The difference between a basic fare and a changeable one may be less than a single change fee.
• Check the 24-hour rule. Some jurisdictions give a window after booking to cancel for free. Rules differ, and not every airline or route is covered.
• Consider travel insurance carefully (see fee #12) and read what it covers.
• Screenshot the fare rules at booking, so you have the terms that applied when you bought.

9. Name Correction Fees

Typical cost: Often $30 to $150+ per passenger.

You typed your name incorrectly, or it does not match your passport exactly. Fixing it can cost real money.

Why it catches people

A misspelled name is one of the easiest mistakes to make while rushing through checkout. Budget airlines frequently treat corrections as a paid service. Some allow small fixes for free within a short window, and others charge more for larger changes. Some treat a full name change as a new booking.

The problem is worst on international flights, where the name on your ticket must match your passport. Using a nickname, leaving out a middle name when your document shows it, or swapping first and last names can cause problems at check-in.

How to avoid or reduce it

• Have your passport or ID in front of you while booking.
• Type each name exactly as written on the travel document.
• Check autofill. Browsers sometimes fill in a nickname or a different name format.
• Review every passenger’s details before paying.
• Contact the airline quickly if you notice a mistake. Some carriers allow minor corrections for free or for a small fee shortly after booking, and the cost can rise as departure nears.

10. “Drip Pricing” Charges: Passenger Service, Fuel, and Administrative Fees

Typical cost: Varies widely and may be a mix of mandatory taxes and optional-looking charges.

The headline fare is not always the full fare. Between the search results and the payment page, extra line items appear.

Why it catches people

Some of these are legitimate government taxes and airport charges that the airline collects on behalf of authorities. Others are airline-imposed fees with names like “passenger service charge,” “fuel surcharge,” or “administration fee.” The distinction matters, but the consumer experience is the same: the price goes up.

This practice is often called drip pricing, where costs are revealed in stages. Regulators in several countries have taken an interest in making total prices clearer, though rules and enforcement differ by location and change over time. In the EU, airlines are required to show the final price, including taxes and unavoidable fees, when they display fares. Elsewhere, the rules vary.

How to avoid or reduce it

• Always look at the full price breakdown. Scroll to the final summary before you enter payment information.
• Compare totals across airlines, not the first number you see.
• Use a fare comparison tool that shows total prices, and then confirm on the airline’s site.
• Ask what each charge is. If something looks like a made-up fee, check the airline’s fee page or contact support.
• Screenshot the breakdown at each stage for your records.

11. Onboard Food, Drinks, and Water

Typical cost: Often $3 to $15+ per item, with water and snacks priced at a premium.

On many budget airlines, nothing on the plane is free. That can include water.

Why it catches people

You are a captive customer. Prices onboard are usually higher than at an airport shop or a supermarket. On a long flight, a drink, a snack, and a meal can add up to more than you would pay on the ground.

Some airlines also restrict outside food and drink, or have rules about what you can bring on certain routes, so check the policy. Most airlines allow you to bring your own snacks through security (subject to security rules on liquids), and carry-on food is common.

There are also pre-order meals offered at booking. These can be cheaper than buying onboard, but they are not always a bargain compared with buying food at the airport.

How to avoid or reduce it

• Bring an empty reusable bottle and fill it after security.
• Pack snacks. Dry foods like nuts, granola bars, sandwiches, and fruit generally travel well. Check restrictions for the destination country, since some places limit bringing fresh food across borders.
• Eat before you fly if the flight is short.
• Compare the pre-order price with airport prices before adding a meal at booking.
• Check for allergens and special diets. Onboard options may be limited, so bringing your own is often the safest approach.

12. Travel Insurance and Other Pre-Checked Add-Ons

Typical cost: Often $10 to $50+ per passenger, depending on the policy.

During checkout, you may be offered travel insurance, sometimes with an option already selected. You may also see offers for SMS flight alerts, rental cars, hotels, or airport transfers.

Why it catches people

Pre-selected boxes and “opt-out” designs rely on speed and inattention. In some regions, regulations limit this kind of default. In others, you must actively untick the option.

Insurance can be genuinely useful, especially for expensive international trips. But the policy offered at checkout is not always the best value, and coverage may be narrower than it appears. Common exclusions include pre-existing conditions, certain cancellation reasons, and specific activities. Many travelers also already have coverage through a credit card or an existing policy and do not realize it.

How to avoid or reduce it

• Untick everything you did not intend to buy. Read each screen.
• Check your credit card benefits. Some cards include trip delay, cancellation, or baggage coverage when you pay for the fare with them.
• Compare independent policies. Third-party insurers often provide wider coverage for a similar or lower price.
• Read exclusions and limits before buying any policy.
• Skip SMS alerts if you can get the same information from the airline’s app or website for free.

13. Fare Bundles and Third-Party Booking Site Markups

Typical cost: Bundles may range from about $20 to $100+ per passenger, per flight, while third-party sites may add service fees or markups.

Many budget airlines sell “bundles” that group extras together, such as a carry-on, seat selection, and priority boarding. Online travel agencies (OTAs) and booking sites add another layer.

Why it catches people

Bundles are not always a deal. They can be, if you would have bought all the items inside. But if you only wanted one or two of them, a bundle can cost more than buying them individually. Airlines often highlight the bundle as the “recommended” option, which nudges you toward spending more.

Third-party sites can show a lower base fare, then add their own service fees, payment fees, or add-on charges. They can also complicate changes and refunds. When something goes wrong, you may have to deal with the agent and the airline separately, which can mean long waits and unclear responsibility.

How to avoid or reduce it

• Price the bundle against à la carte. Add up what you would pay for each item separately.
• Book directly with the airline when you can. Booking direct often makes changes and cancellations simpler.
• Use search engines for comparison only, then check the airline’s own site for the final price.
• Read the OTA’s fee disclosure, and look for hidden service charges before paying.
• Keep your confirmation and the airline’s booking reference, so you can manage the trip directly with the carrier.

14. Currency Conversion and Foreign Transaction Fees

Typical cost: Often 1% to 4% of the purchase, depending on the method.

If you book on an airline’s site that is not in your home currency, the way you pay can quietly add several percent to the cost.

Why it catches people

There are two common sources of this cost.

Dynamic currency conversion (DCC): The airline or payment page offers to charge you in your home currency instead of the airline’s currency. It sounds helpful, but the exchange rate used is often worse than your bank’s rate, and the markup is built in.

Foreign transaction fees: Your own bank or card issuer may charge a fee on purchases made in another currency or processed abroad, often around 3%.

On a big family booking, either can add up to a noticeable amount.

How to avoid or reduce it

• Choose to pay in the airline’s local currency if given the choice, and let your card network convert it. This is usually the better rate than DCC.
• Use a card with no foreign transaction fees.
• Check whether a debit card or multi-currency account gives you a better rate.
• Compare totals in both currencies before paying.
• Track the exchange rate if you are booking far in advance.

Quick Reference: Budget Airline Fees at a Glance

Ranges are illustrative. Always confirm current prices with your airline.

How to Compare the True Cost of a Budget Airline vs. a Full-Service Airline

The base fare tells you very little. Here is a simple way to compare.

Step 1: List what you actually need. How many bags? Do you need seats together? Will you need flexibility? Do you want food?

Step 2: Price the budget airline with those extras. Add the carry-on or checked bag, seats, payment fee, and any other must-haves to the base fare. Do this for every passenger and every flight segment.

Step 3: Price the full-service option. Look at the all-in fare, noting what is included: bags, seats, snacks, changes.

Step 4: Consider the airport and timing. Budget airlines sometimes use secondary airports that are farther from the city. Ground transport costs and travel time can offset a lower fare. Also factor in departure times, since very early or very late flights can mean extra hotel or taxi costs.

Step 5: Risk factor. A cheap, inflexible fare is a good deal when your plans are certain. If there is a chance you will change them, a flexible fare may be the cheaper option in practice.

A simple example: Imagine a budget flight at $49 each way, plus a $45 carry-on each way, plus a $15 seat each way, plus a $15 payment charge. Your $98 round trip becomes roughly $218 before taxes, which you may not have noticed. If a full-service airline offers a $190 round trip with a carry-on and seat included, the “expensive” airline wins. Your numbers will vary, but the method holds.

Pre-Booking Checklist: 12 Questions to Ask Before You Click “Book”

Run through this list on the final checkout page.

1. What does my fare include? Personal item only? A carry-on?
2. What are the exact bag size and weight limits? Have I measured my bag?
3. Do I need a checked bag, and have I added it now rather than later?
4. Do I need to sit with my companions? If so, have I priced adjacent seats?
5. What is the online check-in window, and what is the penalty for missing it?
6. Is priority boarding something I need, or something that was added by default?
7. What payment fees apply to my method? Is a different method cheaper?
8. Are my names exactly as they appear on my passport or ID?
9. What are the change and cancellation terms for this fare?
10. Have I unticked every add-on I do not want, including insurance and alerts?
11. Am I paying in the right currency, and what will my bank charge?
12. Does the total on the last screen match what I calculated? If not, why?

Taking two minutes to answer these can save you far more than the time it costs.

Smart Habits That Save Money on Every Budget Flight

Beyond the individual fees, a few habits help consistently.

Travel light on purpose. The cheapest bag is the one you do not pay for. Packing a small, versatile wardrobe, using packing cubes, and wearing your bulkiest clothes on the plane makes a personal-item-only trip realistic for many short trips.

Book bags and seats at the same time as the fare. The price of nearly every add-on rises as you move from booking to check-in to the airport.

Take screenshots. Capture the fare rules, price breakdown, and confirmation. If a dispute arises, you will have evidence of what was shown at the time you booked.

Set a total budget, not a fare target. Decide what you are willing to pay in total for the trip, then judge each option against it.

Use the airline’s app for check-in and boarding passes. It often avoids desk fees and gives you updates on gate changes and delays.

Know your passenger rights. Rules differ by country and region. Look up the protections that apply to your flight, including what you are owed for cancellations, long delays, and denied boarding.

Read the airline’s fee page once. Every budget airline publishes a fee table. Reading it for your carrier takes a few minutes and tells you precisely what to expect.

Be careful with “sales.” A big discount on the base fare does not change the add-on charges. Check the final price.

Frequently Asked Questions

What are the most common hidden fees on budget airlines?

The most common are fees for carry-on bags, checked bags, seat selection, airport check-in or boarding pass printing, and payment processing. Overweight baggage, name changes, and flight changes can also be expensive. The best defense is to read the fee table and the final price breakdown before paying.

Is it cheaper to pay for a bag online or at the airport?

Almost always online. Most budget carriers price bags lowest at booking, higher after booking, and highest at the airport or gate. Decide what you need before you buy your ticket.

Do all budget airlines charge for carry-on bags?

No. Policies vary by airline and region. Some charge for any bag larger than a personal item, some include a small carry-on, and some include one only on certain fares. Check the specific airline and fare type.

Are budget airlines actually cheaper once you add fees?

Sometimes. If you travel with only a personal item and do not need seat selection or flexibility, budget airlines can be dramatically cheaper. If you need bags, seats, and flexibility, the total can match or exceed a full-service airline. Compare total costs for your specific trip.

Can I get a refund on a budget airline ticket?

It depends on the fare, the airline, and the reason. Many cheap fares are non-refundable if you cancel voluntarily. If the airline cancels or significantly changes your flight, you may be entitled to a refund under local rules. Check the regulations that apply to your route and the airline’s own policy.

What happens if my carry-on is too big at the gate?

You will likely be asked to pay a gate-check or oversized bag fee, which is typically the most expensive way to add a bag. Measure your bag, including wheels and handles, before you travel.

How can I avoid paying for seat selection?

If you do not mind where you sit, skip it and accept the airline’s assignment at check-in. If you are traveling with a group, weigh the cost against the risk of being separated, and check the airline’s policy on seating young children with adults.

Is travel insurance from the airline worth it?

Sometimes, but it is worth comparing. Check what your credit card or existing policy already covers, and compare independent insurers. Read exclusions carefully before buying.

Do I have to check in online for a budget airline flight?

Many budget carriers require or strongly encourage online check-in and may charge a fee for check-in at the airport. Policies are changing, so read your airline’s current rules and complete check-in as soon as it opens.

What’s the best way to compare budget airline prices?

Use a comparison tool to find options, then go to each airline’s site and build the full booking with the extras you need, stopping before payment. Compare the final totals, including payment fees and baggage.

Final Thoughts: Budget Airlines Are a Tool, Not a Trap

Budget airlines have made flying accessible to millions of people. For a light packer on a short, fixed-date trip, they can be an excellent deal. But the business model depends on the gap between the fare you see and the price you pay, and that gap is where travelers lose money.

The 14 fees in this guide cover most of the ways a cheap ticket becomes an expensive one: bags (carry-on, checked, and overweight), seats, check-in and printing, priority boarding, payment charges, changes and name corrections, drip-priced surcharges, onboard food, upsold insurance, bundles and third-party markups, and currency conversion.

The playbook is simple:

• Decide what you need before you search.
• Compare the total price, not the base fare.
• Pay for extras online, at booking, when they are cheapest.
• Read every checkout screen and untick what you did not ask for.
• Screenshot the terms and keep your records.

Do those five things consistently, and you will keep most of the savings that made you click on the cheap fare in the first place. Next time a $39 flight appears, you will know exactly what to look for before you click “Book.”