I seem to remember going through passport control and customs going from T3 to T1...

However, this particular upcoming trip, we arrive from the US and connect to a GB Air flight to Morocco that seems to leave out of T1. Anyway must we go through those morning lines if we're NOT actually entering the UK or Europe? Will do what it takes, but if standing in line to do UK formalities isn't necessary, would prefer to avoid.

Also, if you DO have to go through the process... must you claim baggage and recheck it? With the one carry on rule, would prefer to check bags all the way through to Casablanca and I think we can as GB Air seems to be a BA subsidiary (we start on AA). However, if this were being treated as a Int'l to domestic/intra-Europe sort of entry just to change terminals, I thought perhaps you'd have to present your bags. Or is it just the US that does this at point of entry? We used to carry on only, so I'm not sure.

Anyone?
Thanks!

You don't claim bags, you don't go through UK immigration, you don't pass GO and you don't collect $200.

www.heathrowairport.com should have a schematic about the process.

Sorry, I may be wrong. The Heathrow site says you will need to go through "customs", which means UK immigration in this context.

But you don't need to claim bags if AA tagged it to your destination.

I'm not sure why the Heathrow site says "pass through customs and security". It should just say security.

Patty - I was wondering about that. But some international to international connections at LHR just says security.

I also don't think one needs to enter UK in this case. Something's not quite right with that instruction.

Thank you both for the replies. It was that schematic throwing me off. I couldn't remember one way or the other the last time we went through, although the circumstances were a little different. Then we were connecting to the EU and collecting baggage wasn't a concern, as we had everything in the cabin.

I ran a parallel thread this morning on the Europe board (it kind of fit both categories) and a number of people are in agreement that an airside transfer and security only is the norm, with possible but unlikely contact at a customs booth that's usually unmanned. But bags are put all the way through on the one ticket.

<<< Sorry, I may be wrong. The Heathrow site says you will need to go through "customs", which means UK immigration in this context.>>>

No it doesn't, it means Customs

<<< I'm not sure why the Heathrow site says "pass through customs and security". It should just say security. >>>

Because you do pass through Customs even on a connecting flight. On a connecting flight (except within UK & Ireland) you don't pass through Immigration though you will pass through Security - so lose that 2nd piece of hand luggage and that bottle of duty free Whisky