Here's a detailed look at what you need to know about travelling from London to Paris on the Eurostar. Passports and security checksBritish travellers heading from London to Paris need a valid passport, despite travelling by train rather than plane. Adults travelling in Eurostar Standard can take two pieces of luggage up to 85cm long plus one small piece of hand luggage. Before boarding the London train, passengers go through ticket checks, passport controls, and security in Paris. ConclusionFor anyone considering a city break in Paris, Eurostar is one of the simplest ways to turn two European capitals into one relatively short journey.