I am changing flights at Heathrow. Can I carry liquids, aerosols and gels in my hand luggage that I bought from the duty-free store at my previous airport?
It depends where you bought them. You can carry liquids, aerosols and gels through security at Heathrow if the following applies:
You bought the liquids, aerosols or gels in a passenger-only zone at an airport in the European Union*, Norway, Iceland or Switzerland, or on an aircraft operated by an airline based in one of these countries. Your items must be sealed in a tamper-proof bag provided by the airport or airline, inside of which must be proof of purchase showing that you bought them within the previous 24 hours; OR
You bought the liquids, aerosols or gels in a passenger-only zone at one of the following airports: any international airport in Canada or the USA; Dubrovnik, Pula, Rijeka, Split, Zadar or Zagreb in Croatia; Kuala Lumpur in Malaysia; or Changi in Singapore. Your items must be sealed in a tamper-proof bag provided by the airport, inside of which must be proof of purchase showing that you bought them within the previous 36 hours.
* EU countries are: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden and the United Kingdom.