One of life's occasional frustrations is when BA - or any airline - cancels your flight, or there is a long delay on it. This thread is to help you find out the reason, and indeed feel free to ask questions below about what happened to your BA flight. In some cases it's useful to find out to support a claim for EC261 / UK261 compensation, where "extraordinary circumstances" is a reason why you may be out of scope for compensation. See the main EC261 thread via the BA Forum Dashboard for EC261 / UK261 specific issues.

See also this thread for what to do if your flight is disrupted:
https://www.flyertalk.com/forum/brit...5-edition.html

and for EC261 / UK261 issues and discussions:
https://www.flyertalk.com/forum/brit...uk261-apr.html


Summary version - please read before posting
1) This thread is to find out the reason for delays and cancellations, not to discuss the EC261 / UK261 merits - there is a dedicated thread for EC261 / UK261 discussions. Kindly do not use this FAQ thread for discussions on compensation since people need to be able to find information efficiently in what will turn out to be a long thread.
2) After a delay or cancellation, it's best wait about 24-48 hours to find out whether there is information in this thread - in many cases you don't need to do anything. Broadly all LHR cancellations should be here, LCY and LGW probably need you to raise a question. Normally we manage to capture LHR services - outbound and inbound - so if you wait a few days the information should be there without asking. But by all means post if it hasn't been listed within 48 hours.
3) If you you are flying to London, it's helpful to find out if the flight from London previously was also cancelled: Because almost all BA services start from London we don't tend to list two entries per cancellation, just the London departing cancellation. Often the flight number is one digit different, so BA990 and BA991 is one rotation listed under BA990 only.
4) Rarely there is a cancellation from an out-station to London, so the London to out-station service operated but some technical or crew issue meant the inbound to London service was cancelled. If this applies it's best to ask.
5) If you can't work out what has gone wrong with your service, and particularly after 48 hours, then please ask. Some data only hangs around for a short period.
6) Cancellations come with a four character code, such as WEAN or TECY. The last letter, Y orN, indicates BA's opinion as to whether EC261 applies. The codes are explained below. And just because BA says "no" doesn't necessarily mean that they are correct.
7) Flight Status is an option in both the BA App and the ba.com (under Manage). Strangely the App version can have more information than the ba.com version, in particular weather and ATC related problems.
8) If your issue relates to event from last year, see the end of the thread for last year's version of this thread.

==
Delays - how to find out the cause
1) Listen to the flight deck's announcement just as doors are closing after boarding. On every delayed BA flights that I've been on, the flight deck gives a full description of why there is a delay. It may be worth making a note of what is said, this is by far the best and most accurate report you are going to get. I appreciate that sometimes it's difficult to hear what is being said, but on longhaul you can plug in you earphones to the inflight entertainment system to hear more clearly.
2) Expertflyer - there is a dispatch code put into Amadeus by ground staff with a 2 letter code giving a broad reason code (see codes below). This is found in Desktop version / Flight Status / Search by Flight (the default search). Note this information is only visible for around 48 hours. If you don't have access to Expertflyer then by all means ask below.
3) Flightradar24 - in this website you can enter your flight number and you may be able to identify your aircraft registration (e.g. G-TTNF). By clicking on that registration, or entering it into Search, you can see the previous history of the aircraft and see where delays happened.
4) Twitter - sometimes a search will find out more information if someone else has complained about the delay/

Cancellations
These are more difficult to work out, since if done in advance all you will get from BA is some sort of notification of disruption and often a menu that allows you to choose new flights. In this you will not find clarity on what happened to your original flight - and contact centre staff may not know either. And sometimes, to be brutal, BA doesn't particularly want to go out of its way to say (e.g.) we do not have enough crew members to run this particular service. Expertflyer (see above) used to give information about this, but for the last few months this hasn't generally been visible - I don't know whether that's on the BA side or Expertflyer or a bit of both. All EF shows is that the flight is cancelled. You may alternatively get some clues from Flightradar24, particularly if your route needs a particular aircraft type and the designated aircraft is stuck somewhere else.

Both cancellations and delays
5) Don't forget to scan down the BA forum for a page or two, you may see an existing thread with a lot of information, particularly if something like weather or a computer failure was at fault.
6) Ask at the airport. Agents can look up information for you and a polite request should be met with a useful reply.
7) HADACAB: this is actually a name of an adhoc working group which involves the main operational players at Heathrow. Heathrow ATM Demand and Capacity Balancing group can request all airlines to reduce throughput by a given percentage, often in the 5 to 20% range. BA tends to end up with a higher percentage since some operators, with just one flight a day into LHR, are exempt.


Amadeus dispatch codes - main ones
ZO - Operational - a bit of a catch-all this but it could include late arriving crew. Very often ok for EC261.
ZW - Weather - delays caused by poor weather - generally out of scope for EC261.
ZY - Rotational - a delay caused by a previous delay to services and the aircraft is in catch up mode. Often, but not always, ok for EC261.

Less frequent codes
ZA - ATC
ZC - Cargo
ZD - Security delays
ZE - Engineering
ZF - Flight crew (though usually ZO is used)
ZJ - IT delays (also EO is used here)
ZK - Cabin crew (again more likely ZO is used)
ZL - Ground fleet
ZM - Catering
ZP - Passenger services
ZR - Ramp / apron
ZT - Control (load sheets for example)
ZZ - Authorities / government action

Three and four letter codes
OPE - Operational (all sorts of issues get given this, but crew held up in security would be one example of thousands)
WEA - Weather
ARP - Airport (this can mean weather related restrictions)
FCR - Flight Crew
CCR - Cabin Crew
COM - Commercial (COMN usually means a flight BA cancelled some time ago, typically over 2 weeks, so avoiding EC261 compensation)
IND and INR - Industrial / strikes
ITS - IT system failure
HLD and HDL - ground handing
ROT - Rotational (delay due to delay on previous flight)
TEC and TCH - Technical problems on the aircraft
DAM - Damage (e.g. lightning strike)
ODR - Odour related event - typically smoke in the cockpit on a previous flight
SCT - Security - such as armed conflict en route.
Note this usually comes over as 4 letters, so OPEY means operational and potentially yes to EC261. WEAN - means bad weather and no EC261, at least from the airline's perspective
==
Just to reiterate - by all means ask here for more help and assistance for why your flight is late after going through the above, but for EC261 specific enquiries there is a thread for those queries and it's best to put them in that thread rather than spreading information all over the forum. Last year's 2025 thread can be found here:
FAQ : Reason for flight delay or cancellation - 2025 edition

Thursday 1 January 2026

No BA cancellations so far for LHR, the only technically "on the day" cancellations for the airport are the domestic Loganair flights to DND and LDY, which should have been pre-programmed out of the schedule long ago. 334 BA flights due out of 638 for the airport. So far the punctuality today has been bad, if not as a bad as yesterday, due to poor weather conditions. Regulation has been cancelled at 08:45 hrs so hopefully things will improve.

Morning Operational Update
Landing RWY: 27R
Airborne holding (mins): 11 peak
Departure RWY: 27L
TSAT delay average (mins): 0
Heathrow: 44/60 0630-1100z due capacity.
Network: LFPG (LVP), EHAM (winds)
Weather: Ground and Air Frost Warning until 0900z

Thursday 1 January 2026 - update

BA1490 GLA = OPEY - aircraft was previously from ARN and delayed by bad weather there, and so they scrapped the GLA leg to keep the FRA night stop service on time.

==
Friday 2 January 2026

BA436 AMS = WEAN
BA964 HAM = WEAN
- this being weather at the destination

BA243 MEX - delayed overnight, now expected to depart at an unusual 08:45 hrs on Wednesday, due to technical issues with the aircraft.

Bad day for punctuality, just 45% of services were on time. BA had 337 departure, out of 661 departures for LHR as a whole.

Afternoon Operational Update:
Landing RWY: 27R
Airborne holding (mins): 8
Departure RWY: 27L
TSAT delay average (mins): 13 mins due Di-icing.

Network: 56 Regulations across Europe.
Aerodromes: EHAM (Amsterdam) regulated due to adverse Weather conditions (Wind, snow). - Very High delays. No improvements.
ESSA (Stockholm) regulated due to Weather (Snow). Very high delays. Improvements unlikely.
LFST (Strasbourg) Approach sectors regulated due to ATC Staffing -
Airspace: No Significant issues.

Weather: Ground Frost Warning 1700-031100, Air Frost Warning 1900-031100. Dry, sunny and cold for the rest of the day with airframe icing throughout. Temperatures fall quickly late afternoon and early evening with a high risk of ice where surfaces remain damp and untreated from earlier precipitation.

Any delay reason for BA106, DXB to LHR on Jan 3? Landed 2 hours late.
thanks

Rotational delay due to late inbound and well under scope for compensation I am afraid

Both Dubai flights diverted due to bad weather in Dubai.

Glad I am not the only one who gets co fired with days at this time of the year 😊
Yesterdays 243 MEX managed to get away today so no need to wait to Wednesday

Thanks, but caused missed connection to ABZ which does take it over 3 hours.

I�m guessing it�s not you who is travelling as you would have seen the fog?

Indeed, my step-father.
I have the DXB joy next week!

My condolences, I hope it�s a brief day?

Tell me about BA 661 Larnaca - Heathrow. Cancelled as of last night. Aircraft stranded at Larnaca. G-TTNJ

that looks very tech to me, due out now in 21 mins but they haven�t started boarding yet. Arrived yesterday and should have gone today. Doesn�t show as cancelled yet, if it�s yesterdays service you are referring to

Could someone please check the cancellation reason of kl605 today for me? I know it is KLM, but I am trying to help my SIL travelling back from her Christmas break with us. Schipolis a mess due to weather but this was initially showing as delayed due to technical issues…

Right wing problem. Will go via Frankfurt to refuel left wing. Funny, huh?