Know your rights regarding compensation for delayed flights. You can go back 6 years...
There are EU regulations in place ensuring you get compensation for delays or cancellations by EU airlines or by any airlines flying to or from a European airport (I am not sure how Brexit might effect things). Compensation can be significant - up to €600 per person.
You have six years to claim compensation, so worth checking back on any delays!
You are entitled to EU compensation if;
You are delayed in getting to your final destination by more than three hours - many carriers build buffers into their flight times which means they can make up time in case of a delay - it's all about how late you arrive, rather than how late you take off; and
The delay arises from causes within the carrier's control (basically a technical fault) rather than extraordinary circumstances which could not have been avoided by all reasonable measures (such as bad weather). If your flight is delayed be sure to ask the staff why and make a note.
The level of compensation is as follows:
€250 per person for flights of 1,500km or less;
€400 per person for flight within the EU of more than 1,500km and for all other flight between 1,500 and 3,500km;
€600 per person for all other flights.
I have been delayed by more than three hours for technical reasons on a significant number of occasions and putting in a claim and getting paid is very straightforward. For two of you travelling long-haul, compensation is €1,200, which in many cases can be more than the flight cost. Most companies have a form on their website which you need to complete - British Airways can be found here:
Bad weather must affect the ‘flight in question’ in order for airlines to use it as a defense. If your flight was delayed because of the knock-on effects of a different flight being affected by bad weather, your should be entitled to compensation on your flight.
For example, if you are booked to fly from London to Paris, but the airline cancels the flight citing bad weather in Stockholm (where the aircraft was before arriving in London), then you should be entitled to compensation because your flight hasn’t been affected directly by bad weather.
There is case-law to support this which you can cite to airlines if the try to deny you compensation.
Google the case of Frederique Jager Vs EasyJet Airline Company Limited in September 2013.
If you are delayed on a flight by an EU airline or by any airlines flying to or from a European airport by less than three hours, but this causes you to miss your connection so that you can't get to your final destination for more than three hours after you initially expected, you can still claim compensation, so long as both legs of your journey were booked together with the same airline.
Google the cases of Gahan v Emirates and Buckley v Emirates in October 2017.