Check-in windows and boarding passes
Ryanair: online check-in opens 24 hours before (60 hours for some fare types) and closes 2 hours before — airport check-in carries large per-passenger fees. Boarding pass must be on phone app or printed; airport printing is charged.
easyJet: check-in opens 30 days before on many bookings — earlier than Ryanair for seat map planning. Airport check-in fees apply on standard fares if you skip online.
Set phone reminders at check-in open if you want free seat maps before paid inventory fills.
Baggage — personal item vs Priority
Ryanair Value fare: one small bag under seat only (40×20×25 cm) — no overhead wheelie without Priority/Flexi Plus or paid 10 kg cabin bag option.
easyJet: similar tiering — standard fare includes under-seat bag; larger cabin bag needs extra purchase or fare bundle including Speedy Boarding.
Measure at home with a tape — sizers at gate are unforgiving. Soft bags that exceed by centimetres get charged full gate rate.
Checked bags: always cheaper pre-booked online than at airport. Weight over allowance charged per kilo at premium rates.
Seats, priority boarding, and bundles
Seat fees: lowest at initial booking, higher closer to departure. Families with children — confirm free adjacency before paying (see /guides/uk-airline-seat-selection-together).
Priority boarding: buys overhead bin access on Ryanair/easyJet when you also purchase larger cabin bag entitlement — useless alone if you only have under-seat bag.
Bundles (Flexi, Plus, Inclusive): maths only works if you need every component — seat, bag, priority, change rights. Strip to what you actually use.
Airport and payment traps
Wrong name spelling changes: charged per correction — double-check passport match at booking.
Currency: pay in GBP on UK site when possible to avoid card FX on airline fees. Use a no-FX card for euro-denominated add-ons — /guides/uk-travel-money-spending-abroad.
Secondary airports: "London" airports may be Stansted, Luton, or Southend — factor train cost before celebrating a low fare. /guides/best-budget-airlines-europe compares true trip cost.