Connecting flight at Heathrow

Thank you, Lola!! I just got word from the travel agent that it is considered one ticket and British Air should send our bags all the way to SFO. I hope that will be true because it will certainly make it easier. And you do make me feel better, Lola, in saying we have enough time if we move along. You can see that I'm a person inclined to worry - already fretting about the July flight. Thanks so much.

Unfortunately the information you have provided is not sufficient to properly help you. Answers to the following should pin it down. Where is the BA flight from? Need this know your arrival terminal, and whether it is within the common travel area or not. BA flies into 1,3 & 5. United departs from 1 for the direct SFO flight. Is this a single booking or two separate bookings? Are you going to check luggage? BA won't check bags through unless it is a single booking usually, especially outside of Oneworld, which will mean having to go through immigration & customs (if your inward flight is not within the CTA) and re-checking bags.

Transfer from either T5 or T3 to T1 is easy IF you have carryon bags, or IF you bags are checked through (but I don't know if BA will do that). In either case you can stay "airside" by using a dedicated intra-terminal bus to go from one to the other. Follow the purple " flight connections" signs for you departure terminal. Mthe bus will take you there without the need to go through immigration lines. You will have another baggage screening at your departure terminal. Minimum connect time from T5 is 90 minute, 75 from T3. There are instructions on the Heathrow website; just Google Heathrow Flight Connections. If you have checked bags that you need to claim and re-check it is different as you will have to go through immigration.

Thanks for your responses - I see I have some more investigation to do to figure this out. We will have checked luggage - there will be 4 of us - we are taking our 2 granddaughters. A travel agent made the reservations for us because we fly into Heathrow, spend 3 days there (she has us on United), then we fly into Copenhagen. We will be flying back from Copenhagen on British Air and then onto SFO. So, I don't know if this is a single booking or with the travel agent handling it for us if it's 2? I guess I would call United to check this out - arrival gate, etc.?

BA flights from Copenhagen all arrive at terminal 5. Presuming you are on a single itinerary and can check the bags through you would need to follow flight connections, take a bus airside to T1, go through security and and handbaggage check and you will be in the departure lounge. The IATA minimum connection time is 90 mins, which you are well within, so if the BA plane was late you would be put on a later flight. If you aren't on a single itinerary and you have to pick up your bags you would go through immigration, pick up bags, transfer airside via the Heathrow Express, recheck bags in T1, & go through security. This would in general take longer. If the BA flight was late and you missed the connection this would be at your own risk. I daresay you have a decent travel agent who knows the importance of this, but it is worth checking to be sure.

Thank you, Marco. I hope she's a decent travel agent - I've never used one before - always done my own planning. But just yesterday I thought about this for the first time - we've always connected on the same airline - this is a new thing. Kind of scary to think about especially since we will have our 2 granddaughters with us. I don't want it to go wrong.

Confirm with you rtravel agent that it is on one ticket, and then have her confirm that you can check luggage through. If not, or if they throw you a curve when you try to check your bags in Copenhagen and they won't check them through, do not worry. You have enough time, you will just have to move right along. Instead of following the purple signs to "flight connections" you would head to baggage claim-which means you go through immigration/passport control as you are "entering" the UK. After getting through there, go pick up your bags and walk through the customs door into the arrivals hall. Look for the signs to the Heathrow Express, which offers fast and free transfers between terminals. Just make sure you board going in the right direction-toward T1, not toward London.