Originally Posted by
alvinlwh
Something similar happened to me a while back and when I asked about it here, the experts told me there is no need to worry about it and BA pick it up automatically and sort it out. Well... They did, less than 24 hours before the flight and they "just" put me on the next flight the next day, with no compensation nor hotel as it was deemed they informed me well above the 14 days minimum required.
https://www.flyertalk.com/forum/brit...ispreloading=1
Whilst I appreciate your case was some time ago, and hopefully BA is more tuned-in to the law now, the notice period is immaterial if a flight change causes the need for an extra hotel night (and indeed you are still well within the legal period if you wish to claim, but you quite probably no longer have the receipts).
If, in the OP's case, BA's revised timings necessitate a stay is needed then that is claimable. This isn't likely in this specific case because presumably BA will provide something same-day for the onward travel to IST, but as a general principle it has traditionally been an area of EU/UK261 where BA has not excelled and they often need sizeable pokes to comply.