Only 1 in 10 passengers feel fully informed of their rights when a flight is disrupted, according to the UK Civil Aviation Authority. Airlines can owe you up to £520/€600 in cash compensation — and often hundreds more in care costs, meals, and hotels — but most passengers never claim it. This guide covers every right you have under EU261, UK261, and US DOT rules, exactly when they apply, what extraordinary circumstances means, and a step-by-step process for claiming what you’re owed.

Table of Contents

• The Rights Most Passengers Never Use
• Which Rules Apply to Your Flight?
• EU261 and UK261: The Core Rights Framework
• EU261 / UK261 Cash Compensation: Amounts, Thresholds, and Eligibility
• The Care Rights: Meals, Hotels, and Communication (Article 9)
• Your Right to a Refund or Re-routing (Article 8)
• Extraordinary Circumstances: When the Airline Is Off the Hook
• US Passengers: What DOT Rules Give You (and Don’t)
• What to Do Right Now at the Airport
• How to Make a Formal Compensation Claim
• If the Airline Refuses: Escalation Options
• Special Situations: Connecting Flights, Codeshares, and Package Holidays
• Documentation Checklist: What to Collect Before You Leave the Airport
• Conclusion: Your Money Is There — Claim It
• Frequently Asked Questions

EU 261 / UK 261 Compensation By Route Distance

EU vs UK vs US: Rights Framework Comparison

Extraordinary Circumstances: What Counts and What Doesn't

The Rights Most Passengers Never Use

Flight disruptions are one of the most stressful experiences in modern travel. You are at an airport, your plans have collapsed, and the airline’s ground staff are giving you vague information or no information at all. What most passengers do not know in this moment — and what most airlines do not go out of their way to tell you — is that a powerful set of legal rights sits behind that disruption, enforceable against the airline, and in many cases worth hundreds of pounds or euros in cash compensation.

Only 1 in 10 passengers feel fully informed of their rights when a flight is disrupted, according to the UK Civil Aviation Authority (CAA) (skyrefund.com, June 2025). Most passengers never claim what they are owed. Airlines count on this. The compensation amounts under EU Regulation 261/2004 (EU261) and its UK equivalent (UK261) reach €600/£520 per passenger for long-haul disruptions — and that is before adding the value of meals, hotels, and transport the airline must also provide under the same regulations.

This guide gives you the complete picture: which rules apply to your flight, what compensation you are entitled to under EU261, UK261, and US DOT rules, what ‘extraordinary circumstances’ means and how airlines misuse it, what to do at the airport in real time, and how to escalate a claim if the airline refuses to pay. The July 2026 update to EU261’s notification requirements and the February 2026 procedural changes to the EU claims process make this a particularly timely moment to understand your position.

1 in 10: passengers who feel fully informed of their rights (UK CAA; skyrefund.com Jun 2025). EU261/UK261 max compensation: €600/£520 per person for flights over 3,500 km. Delay threshold for compensation: 3+ hours late at destination. Cancellation threshold: informed under 14 days before departure. US DOT refund threshold: 3+ hrs domestic, 6+ hrs international. EU261 procedural improvements: February 2026. EU261 July 2026: airlines now required to actively notify passengers within 96 hours of disruption.

Which Rules Apply to Your Flight?

Before you can understand what you are owed, you need to know which set of rules governs your flight. Three major frameworks exist: EU261, UK261, and US DOT rules. They do not all apply simultaneously, and knowing which one applies is the foundation of any claim.




The most common confusion: passengers flying from an EU airport to the UK on a non-EU airline sometimes assume UK261 applies. It does not — EU261 applies because the departure airport is in the EU. Conversely, passengers flying from the UK to an EU airport on an EU airline may have rights under both regulations for different legs of the journey. When in doubt, the rule of thumb is: the regulation of the departure country applies on the outbound leg; the regulation of the origin country applies on the inbound leg for EU/UK-based carriers.

EU261 and UK261: The Core Rights Framework

EU Regulation 261/2004 — commonly called EU261 (though formally EC261) — has been in force since February 2005. It provides some of the most passenger-friendly aviation rights in the world. After Brexit, the UK retained the regulation in its domestic law, creating UK261 — a near-identical framework with compensation amounts converted from euros to pounds. As skyrefund.com (June 2025) notes: ‘Both regimes give you almost identical protection. Most travellers never claim what they are owed.’

The regulation creates three interlocking categories of rights:

• Article 7: Compensation — a fixed cash payment per passenger based on the flight distance, payable when a disruption is the airline’s fault and the passenger arrives more than 3 hours late at the final destination.
• Article 8: Refund or re-routing — when a flight is cancelled, the passenger can choose between a full refund within 7 days or re-routing to the final destination at the earliest opportunity.
• Article 9: Right to care — regardless of the cause of the disruption (including extraordinary circumstances), passengers have the right to meals and refreshments, accommodation, and transport between the airport and accommodation for as long as they are waiting.

A critical distinction: Articles 8 and 9 apply in almost all circumstances of significant delay or cancellation. Article 7 (cash compensation) only applies when the disruption is the airline’s fault and no extraordinary circumstances apply. Many airlines conflate these — telling passengers that ‘extraordinary circumstances mean you have no rights’ when in fact it only means no cash compensation. Care rights (meals, hotels) apply regardless.

EU261 / UK261 Cash Compensation: Amounts, Thresholds, and Eligibility

The cash compensation under EU261 and UK261 is fixed by regulation — it does not depend on the actual financial loss you suffered, the cost of your ticket, or the airline’s goodwill. It is a mandatory statutory payment. The amounts are:



For compensation to be payable, all of the following must be true:

• You hold a confirmed reservation and checked in on time.
• You were not informed of the disruption 14 or more days before departure (for cancellations), or the disruption was not caused by extraordinary circumstances (for delays and last-minute cancellations).
• You arrived at your final destination 3 or more hours late (for delays), or the flight was cancelled with less than 14 days’ notice.
• Your flight departs from an EU/UK airport, or arrives at an EU/UK airport on an EU/UK-based carrier.

The 3-hour arrival threshold for delays was established by the Court of Justice of the EU in the Sturgeon case (C-402/07). It applies to arrival at the final destination, not departure. A flight that departs 4 hours late but makes up time in the air and arrives only 2 hours 59 minutes late does not qualify. What matters is when the aircraft door opens at your destination.

A passenger booked on a London Heathrow to New York JFK flight (UK261 applies; over 3,500 km) finds the flight delayed by 4 hours due to a technical fault with the aircraft. The technical fault is within the airline's control (not extraordinary circumstances). The passenger arrives 3 hours 45 minutes late. Compensation due: £520 (maximum UK261 amount for long-haul). The passenger also had the right to meals and refreshments during the delay (Article 9). The airline must provide written information about the right to compensation if asked. Note: always get the reason for the delay in writing from airline staff.

At the airport: ask gate staff or the airline desk specifically 'what is the reason for this delay or cancellation?' and request written confirmation. This is critical because if the airline later claims extraordinary circumstances, you will need to be able to challenge that claim. Also photograph or screenshot any departure board showing the delay, and note the time.

The Care Rights: Meals, Hotels, and Communication (Article 9)

Article 9 of EU261/UK261 — the ‘right to care’ — is perhaps the most practically important right for passengers at the airport, because it applies regardless of whether the disruption was the airline’s fault. Even if extraordinary circumstances mean no cash compensation is due, the care rights remain in full force.

What the airline must provide under Article 9, depending on the duration of the delay:

• Delay of 2+ hours (short-haul, up to 1,500 km), 3+ hours (medium-haul, 1,500–3,500 km), or 4+ hours (long-haul, over 3,500 km): meals and refreshments in reasonable relation to the waiting time. In practice this means meal vouchers for use at airport restaurants, or equivalent.
• Overnight delay requiring an additional night’s stay: hotel accommodation, plus transport between the airport and the hotel (both directions). The airline must arrange and pay for this — you should not have to book and pay out of pocket, but if you do, keep all receipts and claim reimbursement.
• Two telephone calls, fax messages, or e-mails (or equivalent): free communication so the passenger can notify family, connections, or travel insurance.

The Lloyds Bank / consumer protection principle applies here: if the airline fails to offer care and you have to pay for it yourself (meals, hotel, transport), you have the right to claim these costs back. Keep every receipt. Reasonable costs are recoverable — which means a hotel room at the airport, not a five-star suite across town. The European Commission’s guidance suggests that accommodation costs should be reasonable and proportionate.

Some airlines attempt to limit care rights by citing extraordinary circumstances. This is legally incorrect. Article 9 care rights are not subject to any extraordinary circumstances exception under the regulation. Meals and hotels are owed regardless of why the flight was delayed or cancelled, as long as the delay is long enough to trigger the care threshold. If airline staff tell you 'we don't have to provide anything because it's extraordinary circumstances', they are wrong about the care rights and you should document the refusal and claim the costs yourself.

Your Right to a Refund or Re-routing (Article 8)

When a flight is cancelled, Article 8 of EU261/UK261 gives passengers a clear choice that the airline must present:

• Option A — Full ticket refund: a refund of the full cost of the ticket (or the unused portion) within 7 days, for the parts of the journey not travelled. This includes a return flight to the original point of departure if you are stranded mid-journey.
• Option B — Re-routing: re-routing to your final destination at the earliest opportunity under comparable conditions, OR re-routing at a later date convenient to the passenger subject to seat availability. The airline must provide this at no additional cost, regardless of whether the alternative flight is on a different airline or a higher fare class.

Importantly, if you accept a voucher or alternative flight without expressly reserving your right to cash compensation, you may inadvertently waive your Article 7 compensation entitlement in some circumstances. The safest approach is to accept re-routing while explicitly writing (by email) that you are accepting the alternative flight under protest and reserving your right to statutory compensation under EU261/UK261.

For significant delays (as opposed to cancellations), Article 8 also applies: if a delay extends to 5 hours or more, you have the right to abandon the trip entirely and receive a full refund, plus a return flight if you are stranded en route. This is distinct from Article 7 compensation — it is a refund right, not a compensation right, and it applies even in extraordinary circumstances.

Extraordinary Circumstances: When the Airline Is Off the Hook

The term ‘extraordinary circumstances’ is the most widely misapplied and most frequently misused concept in passenger rights law. Under EU261/UK261, extraordinary circumstances exempt the airline from paying Article 7 cash compensation — but they do not remove the Article 8 refund or Article 9 care obligations. Understanding what does and does not qualify is essential.

What DOES count as extraordinary circumstances (airline not liable for cash compensation, but care rights still apply):

• Severe weather: heavy storms, extreme snow, fog, hurricane conditions, volcanic ash clouds (such as the Icelandic ash cloud events). Note: routine winter snow at northern European airports is sometimes contested — if snow is foreseeable and the airline was unprepared, the extraordinary circumstances defence may not hold.
• Air traffic control (ATC) strikes: strikes by ATC staff at the relevant airport or en route, or ATC capacity restrictions beyond the airline’s control.
• Political instability, security threats, civil unrest at the departure or destination airport.
• Bird strikes affecting the aircraft.
• Security risks or hidden manufacturing defects not discoverable through normal maintenance.

What does NOT count as extraordinary circumstances (airline IS liable for cash compensation):

• Technical problems with the aircraft: the Court of Justice has consistently held that mechanical failures are part of normal airline operation and are not extraordinary circumstances, unless arising from an external unexpected event (e.g. damage from a third party).
• Airline staff strikes: industrial action by the airline’s own pilots, cabin crew, or ground staff is within the airline’s sphere of management and does not exempt it from compensation liability under EU law (ECJ Krüsemann and Others v TUIfly, C-195/17, 2018).
• Crew shortages or scheduling failures.
• IT system failures or software outages at the airline.
• Overbooking: if you are denied boarding because the flight was oversold, extraordinary circumstances cannot be invoked.

The withautopilot.com May 2026 guide summarises the practical rule: ‘If the plane broke down or they couldn’t find a pilot, you’re getting paid.’ The burden of proving extraordinary circumstances rests with the airline — not the passenger. Airlines frequently claim extraordinary circumstances for events that do not qualify. If the airline refuses compensation on extraordinary circumstances grounds, always challenge it.

Airports with chronic congestion — like Chicago O'Hare, Athens, or Lisbon — frequently generate delays that airlines attempt to classify as extraordinary (ATC or capacity issues). But courts have increasingly rejected blanket extraordinary circumstances defences at chronically delayed airports, as the heygyro.com August 2026 analysis notes: 'Don't assume congestion automatically counts as extraordinary circumstances — it frequently doesn't.' If your airline cites airport congestion as extraordinary circumstances, it is worth challenging, particularly if that airport is known for routine delays.

US Passengers: What DOT Rules Give You (and Don’t)

US passengers flying on domestic routes or on non-EU/non-UK airlines from non-EU/non-UK airports operate under a different and generally less generous framework. The US Department of Transportation (DOT) provides important protections but does not — as of September 2026 — mandate cash compensation for flight delays, even lengthy ones caused by the airline.

What US DOT rules DO provide:

• Automatic refund for significant delays: if your domestic flight is delayed 3+ hours, or your international flight is delayed 6+ hours, and you choose not to travel, you are entitled to a full refund regardless of the ticket type (even non-refundable fares). This DOT rule was strengthened and clarified in 2024. As withautopilot.com (May 2026) notes: ‘Under US DOT rules, a domestic flight delayed 3+ hours or an international flight delayed 6+ hours qualifies for an automatic cash refund (if you choose not to travel).’
• Tarmac delay limits: domestic airlines must return to the gate or allow passengers to deplane after 3 hours on the tarmac; international flights have a 4-hour limit. During tarmac delays, airlines must provide water, food, and working lavatories after 2 hours (aviatopia.com, August 2026).
• Voluntary commitments: following significant DOT pressure, almost all major US airlines now voluntarily provide meals, accommodation, and free rebooking for airline-caused delays and cancellations (controllable disruptions). However, these are voluntary commitments, not legal mandates, and airlines can change them.
• 24-hour cancellation rule: US airlines must allow passengers to cancel a reservation without charge within 24 hours of booking, provided the flight is at least 7 days away.

What US DOT rules do NOT (currently) provide: mandatory cash compensation for delayed or cancelled flights. A DOT proposed rule from 2024 would have introduced cash payments for airline-caused disruptions, but this proposal was withdrawn in November 2025 (Federal Register, cited squaremouth.com, February 2026). There is no current regulation requiring US airlines to pay passengers the equivalent of EU261 compensation. For US passengers: travel insurance is therefore significantly more important, and the voluntary airline commitment dashboards (available on the DOT website) are the best tool for understanding what your specific airline has committed to provide.

What to Do Right Now at the Airport

When a flight is delayed or cancelled, the actions you take in the first minutes and hours determine both your immediate comfort and your ability to claim compensation later. This is the real-time response guide:

• Step 1 — Do not leave the airport or accept any offer without reserving your rights: if an airline representative offers you a voucher, alternative flight, or accommodation, accept the practical help you need but state explicitly in writing (text message to the airline’s email address, or written note to the agent) that you are accepting this under protest and reserving all statutory rights under EU261/UK261.
• Step 2 — Get the reason in writing: ask airline staff specifically for the reason for the cancellation or delay, and ask them to provide this in writing (letter, email, or printed notification). The reason the airline gives will determine your compensation eligibility. If they cite extraordinary circumstances verbally, insist on written confirmation. Photograph or screenshot the departure board showing the delay.
• Step 3 — Request your Article 9 care entitlements immediately: if the delay has reached the applicable threshold (2 hours for short-haul, 3 for medium, 4 for long), ask the airline desk for meal vouchers and, if required, hotel accommodation. If they refuse, note the time, the name of the agent if possible, and go ahead and purchase your own meals, keeping all receipts.
• Step 4 — Record everything: your flight number, the scheduled and actual departure/arrival times, any announcements made, communications from the airline, and names of any staff who speak to you. The more documentation you have, the stronger your compensation claim.
• Step 5 — Contact the airline in writing within 24 hours: send an email to the airline’s customer service address stating the facts and reserving your right to compensation. This creates a timestamped record. Keep a copy.

How to Make a Formal Compensation Claim

Once you are home, the formal claim process begins. For EU261 and UK261:

• Step 1: Check your eligibility. Use one of the free eligibility checkers provided by AirHelp, SkyRefund, or SkyRefund — they cross-reference flight data to confirm the actual delay at your destination and whether the airline’s stated reason qualifies as extraordinary circumstances.
• Step 2: Write to the airline directly. Under EU261/UK261, you must first give the airline an opportunity to resolve the claim. Write a formal letter or email citing the specific flight, the delay or cancellation, and the compensation amount claimed under the relevant article and distance band. Reference the regulation specifically: EU261/2004 or UK Regulation 261/2004 as retained in UK law.
• Step 3: The airline has 8 weeks to respond under UK CAA guidelines. Keep a record of your communication. If the airline does not respond within this timeframe or rejects your claim, escalate.
• Step 4: If the airline refuses and the flight was UK261-governed, escalate to an Alternative Dispute Resolution (ADR) scheme. UK airlines must participate in an ADR scheme approved by the CAA: CEDR (Centre for Effective Dispute Resolution) and Aviation ADR are the main two. ADR is free to passengers and binding on airlines.
• Step 5: For EU261 claims at EU airports, escalate to the relevant National Enforcement Body (NEB) of the departure EU country. These are free and have legal authority.

Claim time limits: in England and Wales, you can claim up to 6 years back under the Limitation Act 1980 (5 years in Scotland; 6 in Northern Ireland). For EU261 claims, the limit varies by country — 2 years in Germany, 3 in France and Netherlands, 5 in Sweden. Do not assume that a delay from 2 years ago is time-barred without checking the specific country’s limitation period.

Free vs paid claim services: organisations like AirHelp, Flightright, SkyRefund, and Skycop handle claims on a no-win, no-fee basis but typically take 25–35% of the compensation awarded. For straightforward claims where the airline is clearly liable and the documentation is clear, claiming directly costs nothing and takes less time. Use a no-win, no-fee service if you have been rejected and want professional assistance, or if the paperwork is complex.

If the Airline Refuses: Escalation Options

Special Situations: Connecting Flights, Codeshares, and Package Holidays

Several common travel scenarios create specific complications for passenger rights claims:

• Connecting flights: if you miss a connection and arrive at your final destination 3+ hours late, EU261/UK261 compensation is based on your total delay at the final destination — not at the intermediate airport. A missed connection caused by the first flight’s delay is treated as a delay to the whole journey, and the compensation is based on the total distance of the booking, not just the leg that was delayed.
• Codeshare flights: you are protected by EU261 if the departure airport is in the EU, regardless of which airline’s ticket you hold. The operating carrier (the airline that actually flies the aircraft) is responsible for compensation, not the ticketing airline. Always check which airline is operating your flight, not just which airline issued your ticket.
• Package holidays: passengers on package tours have additional rights under the Package Travel and Linked Travel Arrangements Regulations 2018 (UK) and the EU Package Travel Directive. These can provide additional routes to compensation and care, operating alongside EU261/UK261 rights.
• Third-country flights: if you fly between two countries that are neither EU nor UK nor US, check the local regulations. Many countries (Canada, Brazil, Australia, India) have their own passenger rights frameworks, though generally less generous than EU261.

Documentation Checklist: What to Collect Before You Leave the Airport

Your claim strength is directly proportional to the evidence you collect at the time of disruption. Once you leave the airport, some of this evidence may become unavailable.

• Boarding pass or booking confirmation (digital or printed) showing your flight number, booked departure time, and seat number.
• Photograph of departure board or flight status screen showing the delay or cancellation.
• Written notification from the airline (paper notice, SMS, email, app notification) stating the reason for the disruption.
• Names or staff numbers of airline representatives you speak to about the disruption.
• Receipts for all out-of-pocket expenses: meals, refreshments, accommodation, transport. Photograph them and email to yourself before leaving.
• Record of actual arrival time at your final destination (boarding time, landing time, or time the aircraft doors opened).
• Any vouchers or alternative arrangements offered by the airline, along with any written reservations of rights you made when accepting them.
• Travel insurance details and any excess/excess waiver purchased.

Conclusion

Flight disruptions are frustrating enough without the added injustice of losing compensation you are legally entitled to collect. EU261 and UK261 provide some of the most passenger-friendly rights in the world: fixed cash compensation of up to £520/€600 per person, care rights that apply regardless of cause, and the right to a full refund or re-routing at the airline’s cost. The July 2026 EU procedural updates and the February 2026 claims process improvements make 2026 one of the more favourable environments for passengers asserting these rights.

The barrier is almost always awareness rather than eligibility. Only 1 in 10 passengers feel fully informed of their rights at the time of disruption. Airlines know this, and the behaviour of some carriers in overstating extraordinary circumstances or ignoring claims for months reflects a calculation that most passengers will not follow through. The systematic steps in this guide — document at the airport, write to the airline, escalate to ADR if refused — are how passengers convert their legal entitlement into actual money.

The rules can be complex, and individual circumstances always matter. But the starting point is clear: if your flight was delayed 3+ hours or cancelled with less than 14 days’ notice, and your departure was from an EU or UK airport (or your carrier is EU/UK-based and you were flying to an EU/UK airport), your claim exists. The rest is documentation and persistence.

Frequently Asked Questions

How much compensation am I owed if my flight was delayed?

Under EU261 and UK261, the fixed cash compensation is: £220/€250 per person for flights up to 1,500 km; £350/€400 per person for flights between 1,500 and 3,500 km (or intra-EU/UK over 1,500 km); £520/€600 per person for flights over 3,500 km. These amounts are halved if the airline re-routes you and you arrive within 2 hours (short-haul), 3 hours (medium-haul), or 4 hours (long-haul) of your originally scheduled arrival time. Compensation is only payable if you arrived at your final destination 3 or more hours late, the delay was within the airline's control (not extraordinary circumstances), and your flight qualifies under EU261 or UK261 (departure from EU/UK airport or arrival at EU/UK airport on EU/UK carrier). Note: compensation is per passenger — a family of four on a long-haul flight could be owed £2,080/€2,400 in total.

What are extraordinary circumstances and how do airlines misuse the concept?

Extraordinary circumstances are events genuinely outside the airline's control that cause the disruption. They include severe weather, ATC strikes, political instability, security threats, and bird strikes. When extraordinary circumstances apply, the airline does not owe cash compensation under Article 7 — but still owes care rights (meals, hotels) under Article 9 and refund/re-routing rights under Article 8. Airlines frequently and incorrectly claim extraordinary circumstances for events that do not qualify. Technical faults (including hidden manufacturing defects in most cases), airline staff strikes, crew shortages, overbooking, and IT failures are all within the airline's operational control and do not count as extraordinary circumstances. The burden of proving extraordinary circumstances rests on the airline. If an airline cites extraordinary circumstances to deny your compensation, challenge it — particularly if the cause was a mechanical issue or crew shortage.

Can I claim compensation for a cancelled flight?

Yes. If your flight was cancelled and you were not informed at least 14 days before departure, you are entitled to: (1) Article 7 cash compensation at the applicable rate based on flight distance (unless the cancellation was due to genuine extraordinary circumstances); (2) Article 8 refund of the full ticket price or re-routing to your destination at no extra cost; (3) Article 9 care rights (meals, accommodation, communication) during the wait. If you were informed more than 14 days before departure, you are not entitled to Article 7 cash compensation but can still receive a full refund or re-routing. If the cancellation was due to genuine extraordinary circumstances but you were informed less than 14 days before, you do not receive cash compensation but do receive refund and care rights.

What if I'm travelling in the US — do I get the same protection?

No. US passengers flying on domestic routes or on non-EU/UK carriers without EU/UK departure or arrival airports are governed by US DOT rules, which are less comprehensive than EU261/UK261. US DOT rules provide: a full automatic refund if a domestic flight is delayed 3+ hours or international 6+ hours and you choose not to travel; tarmac delay rules requiring aircraft return to gate after 3 hours domestic/4 hours international; and voluntary commitments from most major US airlines to provide meals, lodging, and rebooking for airline-caused disruptions. However, there is no mandatory cash compensation law in the US equivalent to EU261. A DOT proposed rule to introduce cash compensation was withdrawn in November 2025. Travel insurance is therefore more critical for US domestic travellers than for EU/UK passengers.

How long do I have to make a claim?

For UK261 claims, the time limit is 6 years in England and Wales under the Limitation Act 1980 (5 years in Scotland; 6 in Northern Ireland). This means you can claim for a qualifying delay or cancellation from up to 6 years ago (in England/Wales). For EU261 claims at EU airports, the time limit varies by country: 2 years in Germany; 3 years in France, Netherlands, and Belgium; 5 years in Sweden. Check the specific limitation period for the country of departure. The practical advice: do not delay — claim as soon as possible after the disruption, while your records are fresh and the airline's data is readily available. Claims made years later are harder to evidence and more likely to be disputed.

Should I use a claims management company or claim directly?

You can claim directly from the airline at no cost, and for straightforward cases where the airline's liability is clear, this is the most cost-effective route. Write to the airline's customer service address citing EU261 or UK261, your flight details, and the compensation amount owed. If the airline rejects your claim or ignores it, escalate to the ADR scheme (for UK claims: CEDR Aviation or Aviation ADR) or the relevant National Enforcement Body (for EU claims) — both are free. Only use a no-win, no-fee claims management company (AirHelp, Flightright, SkyRefund, Skycop) if you have been rejected after escalation, if the case is complex, or if you prefer to hand off the process entirely. Their commission is typically 25–35% of the compensation awarded, meaning on a £520 claim you receive approximately £338–£390 rather than the full £520.