In 2017 a million UK passengers were eligible for compensation worth over £380 million, as a result of flight delays or cancellations. If you are affected, EU Regulation 261/2004 (which still applies until March 2019) means you could claim up to 600 euros. This EU law applies if you depart from the UK, another EU country, Iceland, Liechtenstein, Norway or Switzerland, whichever airline you use. It also applies to your return journey if you use a European airline.

If your flight’s delayed for 2 hours or more

Your airline has to give you food and drink, access to phone calls and emails and (if you’re delayed overnight) accommodation and journeys between the airport and the hotel

The airline should give you vouchers for “reasonable” expenses at the airport. Ask someone who works for the airline if you’re not offered any help. If they don’t give you help at the airport, keep receipts for expenses and claim from the airline later.

If your flight’s delayed 3 or more hours

You will then be entitled to compensation, so long as the delay is the airline’s responsibility – for example, if they overbooked or there was a technical fault. You won’t get compensation if it was delayed because of something like bad weather or a strike.

If your flight’s delayed over 5 hours

You don’t have to take the flight if it’s delayed for 5 hours or more. It doesn’t matter whose responsibility the delay is. If you don’t take the flight, the airline legally has to give you a full refund for the flight and any other flights from the airline that you won’t use in the same booking, eg, an onward or return flight. If you’re part-way through a journey, they have to provide a flight back to the airport you originally departed from.

If you do take the flight, you can claim up to 600 euros in compensation if the delay is the airline’s responsibility – depending on the distance and destination of your flight.

If your flight is cancelled

You have the legal right to either a full refund– including other flights from the airline that you won’t use in the same booking – or a replacement flight to get you to your destination. Ask for a refund or replacement at the airport if you can. If not, you can claim from the airline later. You also have a legal right to help with costs or compensation if you’re delayed by 2 or more hours.

If you get a replacement flight, the airline legally has to help you with things you need while you’re waiting at the airport for your replacement flight. The airline should give you vouchers to get these things at the airport. Ask someone who works for the airline if you’re not offered anything.

Claiming from the airline

Contact the airline’s customer services department – this needs to be the airline operating the flight, even if you booked it through another airline.

Write your claim – say what went wrong and what you want the airline to give you. You can download a template letter from the Which? website – search for Which flight compensation.

Keep records – keep receipts, copies of your claim and any response. Take notes if you speak to anyone from the airline.

If you’re not getting anywhere

You can report your issue to the Civil Aviation Authority (CAA) unless the airline is a member of an approved alternative dispute resolution (ADR) body. Contact the Citizens Advice consumer helpline on 03454 04 05 06if you need more help.