Airlines reject more than half of compensation claims submitted directly by passengers. In most cases, it comes down to one thing: the claim letter itself. A poorly worded request gives airlines an easy reason to say no. But, a well-structured letter, with the right legal language and the correct supporting details, is much harder to dismiss. Under EU261 and UK261, airlines operating in Europe and the UK are legally required to pay compensation for delays of three hours or more, but they will not make it easy for you.
Before you start writing, take a few minutes to confirm you are actually owed something. Use AirAdvisor's free tool to check your flight delay compensation eligibility. It will tell you exactly how much to claim and whether your flight qualifies. If you are eligible, compensation for a delayed flight can be worth up to £520 (€600) per passenger.
What to include in your flight delay compensation letter
A compensation letter is a legal document, not a complaint email. Airlines treat them differently, and so should you.
The stronger your letter, the harder it is to reject. That means including every relevant detail from the outset, rather than going back and forth with the airline over missing information.
Before you write a single line, gather the following:
- Your flight number and flight date
- Originally scheduled departure and arrival times
- Departure and arrival airports
- Your booking reference number
- The reason for the delay, if you know it
- The full name of every affected passenger travelling on the same booking
- Your bank details for the compensation payment: account holder name, IBAN, BIC/SWIFT, and account currency
You will also need to state the exact compensation amount you are claiming. Use AirAdvisor's free flight delay compensation checker to confirm the correct figure before you write the letter — it varies by route distance, and quoting the wrong amount gives the airline grounds to query your claim.
Once your letter is ready, send it to the airline's legal postal address — not their general customer service address. These are often different. If you cannot find the legal address on the airline's website, call their customer support line and ask for it directly.
Send the letter by registered post, not standard mail. If the airline later claims they never received your letter, a signed delivery confirmation is the evidence that proves otherwise.
Give the airline 14 days to respond. If you hear nothing, that silence matters. Write down the date you sent the letter and the date the response window closed. You may need both if you escalate to the Civil Aviation Authority (UK) or your country's national enforcement body.
When to send a flight delay letter
The rules differ depending on where your flight departed from and which airline operated it.
Under EU261, you may be entitled to compensation if:
- Your flight arrived at its final destination 3 or more hours late
- Your flight departed from an EU airport, or was operated by an EU airline flying into the EU
- The delay was not caused by extraordinary circumstances genuinely outside the airline's control
Under UK261, the same thresholds apply, with one important difference: compensation is paid in GBP rather than EUR, and you have up to 6 years from your flight date to submit a claim — significantly longer than in most EU countries.
It does not matter whether your flight was for leisure or business, or whether it was domestic or international. Both regulations apply to any eligible passenger on the booking. For some long-haul international flights, you may also have rights under the Montreal Convention, which covers delays and baggage issues on flights between signatory countries.
If you are unsure whether your flight qualifies, use the AirAdvisor compensation calculator before writing your letter. It takes a few minutes and tells you exactly where you stand.
How to write a flight delay compensation letter (free template)
Use the template below as your starting point. Replace every bracketed field with your own details, and make sure you attach copies of your boarding pass and booking confirmation before sending.
Date: [Date of Letter Writing]
RE: [Add Your Booking Reference Number and Passenger Names]
Dear Sir/Madam,
According to Regulation (EC/UK) No. 261/2004, Article 7, I am writing to notify you of my intention to claim compensation for the flight delay I incurred on [flight date] on flight [flight number], and for your reference, my reservation number is [booking number].
The flight was scheduled to depart from [departure airport] at [originally scheduled departure time] and arrive at my final destination [arrival airport] at [originally scheduled arrival time], but it was delayed upon arrival at [arrival airport] by [delay length] hours. You will find a copy of my travel documents for your reference attached.
I can confirm that this delay was not caused by extraordinary circumstances.
As a result, I(we), the ticketed passenger(s), are entitled to €[compensation amount] in compensation. It is expected that I will receive the full amount of this compensation within the next 14 days.
Please deposit the compensation into my bank account directly, the details of which are as follows:
Account Holder (full name):
IBAN:
BIC/SWIFT:
Account currency:
A reply from you within 14 days is required, and if nothing is received, I will need to escalate this issue and seek immediate legal counsel.
Sincerely,
[Signature and Your Name]
[Your email/mailing Address and Phone Number]
This letter can be printed and mailed or can act as a flight delay compensation email template (UK and EU applicable).
Expect to be turned down
Most airlines reject compensation requests the first time. This is not an accident — it is a deliberate strategy. Airlines know that most passengers will give up after a single refusal, so a rejection letter costs them nothing to send.
If that happens, do not treat it as the final word.
A rejected claim can be escalated to the Civil Aviation Authority (UK) or your country's national enforcement body in the EU. You can also pursue the airline through small claims court. Both routes have worked for passengers — but both take time and persistence.
The faster route is to let AirAdvisor handle it. Our legal team has recovered compensation for over 800,000 passengers since 2017, including thousands of cases where the airline had already said no. We know exactly how airlines respond to EU261 and UK261 claims — and how to push back effectively.
We work on a no-win, no-fee basis
If we recover compensation for you, our fee is 30% of the amount collected for flight delay, cancellation, or denied boarding claims, and 40% for reimbursement of out-of-pocket expenses. If we do not win, you pay nothing.
You can also fill out the airline’s form
Sometimes, sending an official letter may not be the appropriate first step to seeking compensation. Depending on the airline you’re dealing with, you may find a flight delay compensation form that’s easily accessible on their website.
You might find a PDF form that you download and complete, or a click-through form where you fill out fields and attach documents directly on the airline’s website. Regardless of how you submit your flight delay compensation form, make sure you get confirmation that it’s been received, either via email or by printing or taking a screenshot of the submission page.
If the airline's form is rejected or ignored, everything in this article still applies, you can follow up with a formal letter or hand the case to AirAdvisor at any point.
Resources & Additional Reading
Some extra resources to help you better understand flight delay compensation:
Flight Delays by Issue
Read more about the most popular flight delay causes:
4 minutes read 
