Heathrow Ends 100ml Liquid Restriction After Completing Scanner Upgrade

Heathrow Airport has removed the long-standing 100ml limit on liquids in hand luggage after completing the installation of new CT security scanners across all its terminals.

With the rollout now finished, passengers departing from the UK’s busiest airport can carry liquids in containers of up to two litres through security without removing them from their bags. Electronic items such as laptops and tablets can also remain in hand luggage, and travellers are no longer required to place liquids in clear plastic bags.

Heathrow says the upgrade makes it the largest airport in the world to fully deploy the next-generation scanners. However, it is not the first in the UK to adopt the technology. Airports including Gatwick, Edinburgh and Birmingham have already introduced similar scanners, while Bristol and Belfast have also increased their liquid limits to two litres.

At many other UK airports, passengers are still allowed to keep liquids of up to 100ml in their bags without removing them, but the higher two-litre threshold has yet to be approved. Some airports that have installed the new scanners are still awaiting authorisation from the Department for Transport (DfT) before lifting the restriction.

A recent report by consumer group Which? noted that the heightened sensitivity of the scanners has, in some cases, resulted in more bags being manually searched after screening.

Heathrow said the technology produces clearer images of cabin bags, allowing security lanes to process thousands of passengers per hour while maintaining strict safety standards. The change applies only to outbound flights from Heathrow, and passengers are advised to check liquid rules at their return airports, as restrictions may differ.

The nationwide transition to the new scanners has been marked by repeated delays and policy reversals. Former prime minister Boris Johnson pledged in 2019 that the 100ml rule would be scrapped by the end of 2022, but the Covid-19 pandemic stalled progress. A later commitment by the Conservative government to complete installations by June 2024 also proved unrealistic for larger airports.

In June 2024, the government instructed smaller airports that had already relaxed liquid rules to temporarily reinstate the 100ml limit, prompting criticism from airport operators. The EU also reverted to the restriction shortly afterwards, contributing to widespread inconsistency and confusion for travellers.

Heathrow chief executive Thomas Woldbye said the airport’s £1bn security upgrade programme would allow passengers to spend less time preparing for screening and more time enjoying their journeys. Among the world’s 10 busiest airports, Heathrow is currently the only one to have fully removed the 100ml liquid limit on international departures.

A DfT spokesperson confirmed that Heathrow had completed its rollout of next-generation security equipment but stressed that airports are responsible for installing and operating scanners. Passengers were advised to check individual airport requirements before travelling and to assume the 100ml rule still applies unless told otherwise.

The Advantage Travel Partnership, which represents travel agents across the UK, said the lack of a unified timeline has caused confusion and frustration for passengers. Its chief executive, Julia Lo Bue-Said, called on airports and government to work together to provide clearer and more consistent messaging on security rules.