Hope this is the right place and that someone can offer some advice.

I am looking at doing a twist on the old BA ex-eu ruse (which isn't playing ball when I plan to travel after Christmas) by flying BUD-DBX-PEK with EK. We will start our trip in the UK and travel to BUD on BA or a similar LCC.

Problem is my wife and daughter have Chinese Passports so I was just wondering how TWOV works there. Is it pretty simple for them to transfer airside without issue whilst I clear immigration to collect and recheck hold baggage.

Another possible issue is Check in staff in the UK refusing boarding due to flights not being on the same PNR - they will just see UK-BUD without a valid visa to enter Hungary, though I suppose that is a different question for a different board.

Any help greatly appreciated, thanks.

As you are connecting non-Schengen to non-Schengen, it will be easy. You will either deplane from LHR to the transit area, and they are set (and you follow the exit signs) or (if bus gate arrival) they will have to follow the transit signs and you the exit. They will just shock the transit security there, as they are very much unused to transit pax these days. I had to wait 10 minutes until they summoned all the neccessary operators it was 4 personnel vs 1 pax (me) But coming in from LHR there might not even be security (but surely from DXB)

I cannot comment if BA would allow you to board, but they should if you produce your onward tix/bp's. Oh, might be a good idea to OLCI/print EK bp's for the transit pax at home, as there is no transit desk (afaik) non-Schengen airside.

I'd try to check luggage all the way to PEK - I don't know if BA and EK interline.

For the record it is also possible to do airside non-Schengen->Schengen transit, but the passport booths are all set up in the other direction, so you'll approach them from behind and will cause more surprises.

It's a small airport, btw.

Many thanks for the detailed response!

I am really not confident with BA giving me answer on the phone and their comments being taken as gospel by check in staff.

I would also predict issues with Chinese immigration on the outward leg so I think we may put a pin in this idea until we apply for a shengen visa next summer.

How are the lounges at BUD?

Yeah, my advice would've been to get a Schengen visa as a backup (and Budapest IS worth a few days on it own right) Even a single entry visa can make a big difference in case of ir-op. BUD (or anywhere else) airside is not somewhere I'd like my family to spend a night.

Lounges - contract lounge on both the Schengen and non-Schengen side, used by most full service airlines. Nothing to write home about. There's also a Mastercard lounge, but I don't know what's needed for entry. I think the Mastercard part is geared towards local card holders (as such lounges usually are)