My sister and I are spending 8 days in London then going to Paris via Eurostar. Do we have to go through customs with our purchases from London? After we spend 6 days in Paris we are taking the Eurostar back to London to go directly to the airport. Do we have to go through customs on our way back?

First time doing anything like this. Like you couldn't tell. Lol

Not only do you go through customs, you also go through immigration. You'll also do both on the way back.

But do reconsider your plan to take the train back in order to catch a flight unless you are going to stay overnight in London before flying. There's nothing so embarrassing as having to buy a brand new one way full cost ticket home as you were delayed in coming from several hundred miles away on the day. If you can change your flight home to start in Paris which means you'll avoid UK immigration & customs, have your luggage checked through to the US and be covered if your flight from Paris is delayed. At the very least fly to Heathrow (assuming your flight home is from LHR) on the first flight of the day.

No.

In principle, there's no limit on the movement of merchandise within the EU.

Very occasionally, there are random inspections or questions concerning weapons, some animal products when there's a health scare or the like.

There is of course an Immigration check, but you didn't ask about that.

What flanner wrote.
There are no customs restrictions or checks within (most of) the EU other than the exceptions flanner mentioned.
You go through immigration/ passport control once each way, and also airport-style security checkpoints to get into the waiting lounges for the trains. For the latter I would calculate some extra time to be on the safe side.

The last incident in Paris was when a British tourist tried to return to London with an unexploded WW1 artillery shell in his baggage (proud purchase from the flea market). But of course this was more a security than a customs issue.

>>The last incident in Paris was when a British tourist tried to return to London with an unexploded WW1 artillery shell in his baggage<<

Sigh. There's always one, isn't there?

"<i>After we spend 6 days in Paris we are taking the Eurostar back to London to go directly to the airport.</i>"

This doesn't make too much sense really. You arrive at St Pancras and then have to cross all of London to catch your flight. How many hours do you have between the Eurostar and check in at LHR?

Can you change your booking to fly home from CDG? If not, go into London the evening before.

It was cheaper to fly into and out of London. Flying into London then flying out of Paris was almost double the amount of $ it was for the roundtrip ticket to and from London. We leave late afternoon to come home. We are leaving early in the morning. We should have plenty of time to get to airport. We are going straight there from the eurostar.

I thank you all so much for your help.

How did you find such a price difference? Did you look at two one-way tickets (always expensive) or did you use the "multi-city" option to search for a roundtrip home to London, Paris to home? It should cost about the same.

For your future reference, 'open-jaw' or 'multi-city' tickets are often around the same price as simple return tickets and would have saved you the extra train fares from Paris to London and then on to Heathrow.

Have a look at sites like kayak and play around with the 'multi-city' options. It's obviously too late for this trip but you might save yourself a lot of trouble in future by using this.

Well all be darn! Next time I'm coming here to you all before I plan a trip.

Even taking the first flight from CDG to Heathrow is a better option then early train to St Pancras - and if you use the same airline or one of it's partners you still might be able to check your luggage through to the US thus removing the need to re-enter the UK

definitely think about alanRow's suggestion. Instead of the Eurostar, you can book a flight from CDG to LHR. You'll most likely be able to check your bags through.