flying from heathrow to paris

I don't know the answer for customs. I think it would depend on whether your ticket is Chicago - Paris with a change in Heathrow or if you're booking separate tickets.

Customs aside, I'd want 90 minutes to just change flights in Heathrow. You often have to ride a bus from the plane to the terminal, another bus between terminals and then long lines to go through security again.

And make sure you have only one piece of carryon luggage with you through security at Heathrow.

You will be able to stay airside so you won't have to go through immigration/passport control. You will have to go through security. How long you'll need to make the transfer depends upon several factors:
1. Will your flight to Paris be on the same airline or on a code share partner airline with the airline on which you'll arrive? If so, your baggage should be checked through. If not, you'll have to collect it and re-check it.
2. The check-in time for the airline you'll be flying to Paris.
3. Which terminal you'll arrive at and which terminal you'll depart from.

For detailed information, go to www.heathrowairport.com. Click on "Airport Information" and then on "Heathrow Connections."

Truthfully, I would double the time. Christmas Day may not have the rush but the staffing may not be there either. Heathrow is a mess. Two weekends back we arrived on BA, on time at noon when there should be a little less pressure. It took an hour to get off the plane. The buses were there but no stairs. Once off the plane it went pretty smooth but it was another 45 minutes before we were out of terminal 4. However, the return, four days later, was smooth. Less than an hour from front of airport to gate. Who knows???

Are you buying a ticket to Paris with a transfer in London or are you buying a separate ticket to Paris?

I have missed a tight connection at Heathrow twice, but have always been put on the next flight. However, it has always been as part of a connection on partner airlines. I've never dared buying a separate ticket for the same day to another destination.

You will have to go through another security check at Heathrow.

thank you all for your feedback. i found out that the first airline will check us all the way through, so hopefully i will not need an excessive amount of time between flights. i'm thinking about booking a flight for 2 hours and 25 min later. sound ok?

That should be OK. Merry Christmas!

Once you know which terminal you arrive and which terminal you depart, go on the website and you can get a detailed map showing the exact steps and approximately how long you will be at each stop.

Hi Sarah, I've flown San Francisco to Heathrow to Paris (and back) many times (mostly on BA) and I would be reluctant to have anything less than 2h 15m to be on the safe side. Starting or ending a European trip with a stressful time at Heathrow is not my idea of fun. Charlie, Lodi, CA

thanks again to everyone who replied. to be on the safe side (allowing for plane delays, etc.), I ended up booking a flight that leaves over 4 hours after my first plane is scheduled to arrive. hopefully that will be good for peace of mind. thanks again! your feedback was very helpful.

If it were not for Christmas, Eurostar through the Chunnel is a good option. Train into London, taxi, if necessary, to the Eurostar station (St Pancras International starting next month) and enjoy some countryside views.