>>If you book separate tickets then you'll have to go through UK passport control <<

No you wouldn't . . . you'd go through flight connections just like everyone else . . .

>>you'd go through flight connections just like everyone else connecting to other flights . . .

As long as you are not entering the UK at that point you would stay airside not have to go through Immigration. However, you need to be careful to stay airside and you may well have to go through security again.

There should be plenty of shops and restaurants to while away a few hours.

Thanks for the the clarification, janisj and nytraveler. I guess having never been to London, just being in the airport will be interesting in itself--as you said, looking at shops, etc. Hopefully running on a good dose of adrenaline.

We flew earlier this year from Phoenix to LHR and then on to Marseille on BA. The gates for the flights were in different terminals and there was a huge amount of construction. We had to take a bus. It took quite a while. The terminal we went to to wait for the flight to Marseille had lots of duty free shops, including Harrods, and places to eat. It wasn't hard to spend a few hours there.

Both BA flights use T-5 which is a massive shopping mall w/ cafes, shops, pubs -- even a Gordon Ramsay restaurant.

If you guys keep it up, I might actually get excited about a few hours at the airport. I do feel better about it. Thanks a bunch.

Does no one else think the 12:40 to ORY is a good idea? When I read it above, I thought it sounded good.

I'll look into ORY flights. Appreciate the tip.

janisj - I get that if you're connecting on the same ticket you don't need to go through immigration, but what about the need to claim and re-check checked bags if you're on separate tickets? Is there baggage claim airside?

zoobie - if you are checking luggage be sure when you check in that you ask that it be tagged all the way to Paris. If they tag it only to London you will have to go through immigration to claim your bag, then go through re-check in for the flight to Paris, then re-clear security. Be sure you have your ticket details for London- Paris with you at initial check in so they know how to tag the bags to your final destination.

What I'd suggest before you book your London-Paris ticket is to call BA and explain what you want to do, ask what is the best way to proceed. At minimum they can link the PNRs, which is not the same a having all flights on the same reservation but does help.

BTW, I also think the flight to ORY is a good option - much smaller and easier to navigate than CDG, closer to town.

>>janisj - I get that if you're connecting on the same ticket you don't need to go through immigration, but what about the need to claim and re-check checked bags if you're on separate tickets? Is there baggage claim airside?<<

First of all the OP said they are carry-on only.

But since both flights are on BA - even though they are different tix it is almost certain the airline would check through.

Could you not call BA and add the second flight to the existing ticket so that it is all one reservation?

If you're only carry-on, then just relax in the terminal. There are far worse airports to have to blow 4+ hours than LHR (CDG is definitely near the top of that list).

And yeah, the nap rooms have twins and singles. You can wipe out jointly or your hubby can crash in a single while you shop the terminal mall, or vice versa (there's enough duty free hooch and other "sin" items [cigars, cigarettes, etc] at LHR to satisfy anyone).

jamikins beat me to it--check with BA, they might well add your connecting flight, problem solved.

I would choose the 12-ish flight into Orly, a very good suggestion.

"..But since both flights are on BA - even though they are different tix it is almost certain the airline would check through."

From a security perspective they may not, as the airline would have no guarantee that the passenger would follow the luggage to Paris. The airline is only obligated to get the luggage to London in accordance with the first ticket being used for that leg of the journey.

"they might well add your connecting flight, problem solved."

They might, but wouldn't they charge a change fee?

Change fee? I don't know and neither will the OP unless she ssks. To me it just seems the most obvious and direct next step.

Why would they charge a change fee? They aren't changing the existing flights. They are adding a flight to an existing reservation. I can't see a problem with that...but the likely have to call and ask BA to do it.

BA might add the second flight to the first, or they may not.

Why ? If the second BA flight was purchased through a discounter or wholesaler or some Agent other than directly from BA, it may have been purchased at a price, or terms and conditions of flight/refund that are different than BA's for that same BA flight. BA's T&Cs for that flight might be more generous (such as covering you for the second flight if the first gets you in late) and therefore they would charge more, hence a change fee or even a price differential top-up.
There might also be an issue with ticket and price coding on the BA system for the second flight that wasn't purchased directly from them.

I would think that the OP has a better chance of putting both flights on one ticket if both flights were bought (separately) directly from BA. In any case, good luck.