Although delayed or cancelled flights can leave travel plans in tatters, passengers do have a number of rights.

If you are flying to, from or between EU countries, European Union rules provide you with the right to compensation, re-booking or refunds on air travel tickets, as well as meals and accommodation while you wait for a replacement flight, if applicable.

These rights always apply if you are departing from an EU country regardless of destination and regardless of whether your airline is European.

They also apply if you are flying to the EU with an EU airline; have a flight change outside of the EU as part of a journey that began in the EU; or have a flight change outside of the EU on a flight destined for the EU with an EU airline.

It should be noted that for these rights to apply, you must be at check-in at the airport a minimum of 45 minutes prior to departure time (unless your airline states otherwise). This applies even if you already know the flight is delayed before leaving home (unless the airline states otherwise).

Your flight must be delayed by at least two hours for any of these rights to apply. You may be entitled to one or more of the following: compensation; food and drink; two or more telephone calls or emails; and accommodation plus transport to and from the accommodation, if applicable.

You are entitled to meals if your departure is:

• Delayed by 2 hours or more on journeys of under 1,500 kilometres
• Delayed by 3 hours or more on journeys of over 1,500 kilometres within the EU and between 1,500-3,000 kilometres which go outside of the EU
• Delayed by 4 hours or more for journeys over 3,500 kilometres outside of the EU

The airline is responsible for providing meals in these cases, but if it does not provide its own service then you can purchase your own meals and apply for a refund. It is therefore important to keep receipts.

If the delay means you are unable to travel until the following day, the airline must provide accommodation and pay for travel to and from the airport.

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You may be entitled to monetary compensation if your arrival is delayed by 3 hours or more. This is dependent on the length and distance of your journey. Compensation of 250 euros can be given for journeys of up to 1,500 kilometres; 400 euros for flights over 1,500 kilometres within the EU and for all other flights between 1,500 and 3,500 kilometres; and 600 euros for all other types of flight.

If you are delayed by 5 hours or more, you are entitled to a refund of your ticket or return flight, but not to a ticket for a different route.

A ‘cancelled’ flight is defined as a flight which the airline decides not to operate, instead changing passengers to other (earliest possible) departures. You are not entitled to compensation for cancellations if the flight is cancelled at least 14 days in advance.

Meanwhile, your right to monetary compensation does not apply to cancellations due to unforeseen circumstances such as natural disasters, strikes or terrorism, but the other rights as detailed above remain in place.

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If your flight is cancelled and does not fall under the exceptions outlined above, you have three options: a refund, a ticket for the next available departure; or a ticket for the same route on a date of your choice (depending on availability).

That can in turn result in the airline being obliged to provide you with meals, accommodation and compensation in line with the rights set out above.

You should also note that the airline is obliged to inform of your rights in writing when a cancellation occurs. For your rights to apply, you should still be at the airport check-in at least 45 minutes before the original scheduled departure – unless the airline has advised otherwise.

If your airline fails to provide the compensation, re-booking, refunds and catering for which your rights provide, you can file a complaint, initially with the airline itself.

If the airline does not respond within four weeks, you can prompt them. If there is still no response after two months, they are at odds with European Commission rules.

In such cases, you can take your complaint further in Denmark to the Danish Transport, Construction and Housing Authority (Trafik-, Bygge- og Boligstyrelsen). To be able to complain to the Danish authority, your flight must have departed in Denmark or arrived in Denmark with an EU airline but from a non-EU country.

If the authority upholds your claim, the airline will be obliged to pay compensation or give you a refund.

If your journey was not in the EU, you must file your complaint with air travel authorities in the country where the delay occurred. Denmark has a three-year deadline for such complaints.

Sources: Forbrugerrådet Tænk, European Consumer Centre Denmark, Trafik-, Bygge- og Boligstyrelsen