If you have been on a flight in the last six years that was with Easyjet, and that was delayed by more than three hours, then you may be entitled to compensation under EU flight delay rules
The EU flight delay regulations cover flights that were delayed more than three hours from their arrival time. This means that a flight can take off four hours late, but if it opens its doors at the arrival airport 2hrs 59 minutes late, then it was not “delayed” long enough for compensation. You can read conditions here https://www.flightdelayclaims4u.com/airlines/easyjet when you can do claim to airlines.
The flights must be from EU airports (or arriving at an EU airport, and be with an airline that is regulated by the EU), for the rules to cover it.
You can put in a claim for a flight going back the last six years if you live in the UK, or five years if you live in Scotland.
There is no fee for putting in a claim. As long as you fill out all of the information that the airline needs to know, you should find that the airline will be willing to pay up. If they won’t, then you can appeal to the ombudsman, and you will have a very good chance of winning. If the ombudsman turns you down, then you can appeal that – and then if that is overturned then you can take the case to court. It would be very unusual for a legitimate claim to get all the way to court – typically, the ombudsman would rule in your favor if you actually had a claim. The option is there, though, and it would be a lot of work when there are limits to the amount of compensation that can be awarded for even a comparatively long flight – and even if you didn’t travel.