If your flight is delayed at departure, you have the right to assistance, to reimbursement and a return flight, depending on the duration of the delay and the distance of the flight.
If you arrived at your final destination with a delay of more than 3 hours, you are entitled to compensation, unless the delay was due to extraordinary circumstances. The airline has to prove this by providing, for example, extracts from logbooks or incident reports. The air carrier should give this evidence to the relevant national enforcement body as well as to the passengers concerned in line with national provisions on access to documents.
Travelling from the UK to an EU country
From 1 January 2021, EU rules on air passenger rights do not apply to cases of denied boarding, cancellations or delays to flights from the UK to the EU if your flight was operated by a UK carrier or another non-EU carrier, even if you booked your flight before this date. However, EU rules continue to apply from 1 January 2021 if your flight from the UK to the EU was operated by an EU carrier, unless you have already received compensation or benefits under UK law.