Originally Posted by Thomathy

Yes. A checked bag can be 90 x 75 x 43 cm. But you can take ‘larger items’ up to 190 x 75 x 65 cm. After check-in, these have to be deposited at the ‘Oversized’ baggage belt (next to the F Wing at T5) and retrieved from the Oversized collection area at the destination. There is no additional charge for checking an oversized item but it is subject to the usual weight limits, and each oversize item counts as one normal bag.

I have done this both outbound from the UK and inbound to the UK, to and from various out-stations, without any problems. Often the items I see others checking via this method are children’s buggies, racing bikes in a bike box, sports equipment and so on. My own experience is from checking large household items, boxed for travel. Note that bikes have their own rules and you need to notify BA in advance that you are carrying one. I haven’t ever pre-warned BA of carrying non-bike large items and this has never been a problem for me.