Budget airlines are cheap until they're not. The headline fare is real, but it's also the floor. By the time you've added a bag, picked a seat, and paid by card, you can double the price. Here's what's coming and how to keep it under control.

The Cabin Bag Trap

Every budget airline now charges for a standard cabin bag — the kind that goes in the overhead locker. On Ryanair, a priority boarding pass (which includes an overhead cabin bag) costs around £6-£8 each way if booked early, and significantly more if added later. On easyJet, a large cabin bag costs around £13 each way if booked in advance, up to £48 if you buy it at the gate.

The free allowance is small: a personal item that fits under the seat in front. Ryanair's free bag is 40x20x25cm. easyJet's is 45x36x20cm. Test your bag against those dimensions before you pack.

The trick: book any paid bag add-on when you buy the ticket. Airport and last-minute prices are punishing.

Seat Selection Fees

You do not need to pay for a seat. Both Ryanair and easyJet will assign you one for free at check-in. The paid options just let you choose where you sit. Fees range from £3 for a random standard seat to £20+ for extra legroom up front.

If you're travelling with someone and don't care where you sit, ignore seat selection entirely. If you're travelling with children, Ryanair is legally required to seat them near a parent, so you shouldn't need to pay for that either.

Check-In Fees

Ryanair charges £55 per person to check in at the airport. That is not a typo. Online check-in opens 60 days before departure and closes 2 hours before. Missing the window is genuinely expensive, so set a reminder or use the app.

easyJet does not charge for airport check-in, but its app check-in is faster and gives you a boarding pass you can actually rely on.

Checked Luggage Costs

Ryanair charges around £8-£40 each way for a 20kg hold bag depending on route and timing. easyJet is similar. Neither includes a hold bag in the base fare. If you need one, book it with the initial ticket purchase. Same-day prices at the airport can exceed £50 each way.

The smarter play for a 3-4 night city break: pack into a personal-item bag and skip checked luggage entirely.

Credit Card and Payment Fees

Ryanair charges a payment fee of around 2% for Visa and Mastercard credit cards. Use a debit card or prepaid travel card (such as Revolut or Starling) to avoid it. easyJet no longer charges payment fees on most cards in the UK.

The Real Total

On a Ryanair booking, a £30 fare becomes roughly £55-£70 once you add priority boarding (with overhead bag) and online check-in is sorted. Add a hold bag and you're at £90+. Still cheaper than most full-service carriers, but only if you book add-ons early and don't miss anything.

Budget airlines make money on the extras. Go in with the full fee schedule open, and you'll usually come out ahead.