Heathrow and Gatwick Scrap 100ml Liquid Rule in Security Shake-Up

London’s two biggest airports, Heathrow and Gatwick, have scrapped the long-hated 100 millilitre liquid rule at security, marking a watershed moment for UK air travel and promising faster queues, fewer plastic bags and a more relaxed start to passengers’ journeys.

New Scanners Bring Landmark Change for London Flyers

The change follows the full rollout of next-generation computed tomography scanners across all security lanes at Heathrow and Gatwick, allowing liquids to be screened in high-resolution 3D while remaining inside cabin bags. The investment, running into the hundreds of millions of pounds, has been years in the making and repeatedly delayed, but both airports now say every standard lane is equipped with the new technology.

Under the updated rules, passengers departing from Heathrow and Gatwick can carry liquids in containers far larger than the old 100 millilitre limit, up to a cap of around two litres per container, provided they comply with existing restrictions on hazardous substances. Crucially, travellers no longer need to decant toiletries into miniature bottles or pack them into single-use plastic bags, a ritual that had become a symbol of post-2006 aviation security.

Airport managers say the shift will not only improve the passenger experience but also help cut the volume of confiscated items at checkpoints. Security officers have long reported that oversized liquids and forgotten plastic bags were among the most common causes of bag searches, secondary screening and missed flights.

The UK government first signalled its intention to phase out the 100 millilitre rule in 2019, tying the change to the widespread introduction of advanced imaging equipment. The pandemic and supply-chain constraints pushed back those plans, but London’s two hub airports are now at the forefront of a broader transition taking place across parts of Europe and beyond.

What Travellers Can Now Carry Through Security

For most passengers, the most tangible difference will be what, and how much, they can bring through security. Full-size shampoo and shower gel bottles, large format skincare products, family-sized sun cream and sealed beverages can now pass through checkpoints at Heathrow and Gatwick, as long as they are in containers within the new, higher volume limit.

Laptops, tablets, cameras and other large electronics can also remain packed inside bags while they are scanned, reducing the number of trays each passenger needs to use and speeding up the flow of people through each lane. Security teams say this should cut down on congestion at the point where travellers traditionally stopped to unpack and repack devices and liquids.

Some familiar rules remain in place. Duty free liquids purchased before security must still follow standard procedures, especially for connecting flights, and certain categories such as flammable liquids, aerosols and chemical products continue to face strict restrictions or outright bans. Medicines and special dietary liquids, such as baby formula, retain their existing exemptions but are now less likely to trigger bag searches purely on volume.

Passengers are being urged to check that bottles and containers are properly sealed, to avoid leaks inside bags that can damage electronics or clothing. While clear plastic bags are no longer required in London’s two largest airports, staff emphasise that organised packing and easy-to-open luggage still help keep queues moving smoothly.

Benefits for Queues, Sustainability and Airport Operations

Airport officials predict that scrapping the 100 millilitre limit will yield measurable gains in both efficiency and sustainability. At Heathrow, managers estimate that allowing liquids to stay in bags will save many millions of single-use plastic security bags annually, cutting down on waste and disposal costs while aligning the airport’s operations with its public climate commitments.

Operationally, the new scanners give security staff sharper, more detailed images of each cabin bag, helping them distinguish benign items such as toiletries or drinks from potential threats without repeated manual checks. This should lead to fewer bags being diverted for secondary inspection and reduce the stop-start pattern that has often frustrated travellers at peak times.

For airlines, smoother security flows can translate into more predictable boarding times and fewer last-minute calls over the public address system for delayed passengers. Retailers on the airside are also expected to benefit, as passengers spending less time in queues may have more time to shop or dine before boarding.

Industry analysts note that London’s move brings it into line with a growing number of airports in Europe that are lifting or easing liquid restrictions as they roll out similar technology. However, they caution that inconsistent rules across different countries and hubs could persist for years, requiring careful communication to avoid confusion for international travellers.

Why the 100ml Rule Lasted So Long

The 100 millilitre limit was introduced across much of the world in 2006, in the wake of a foiled plot involving liquid explosives on transatlantic flights. It quickly became one of the most visible and least popular features of the modern airport experience, spawning an entire industry of miniaturised cosmetics and travel-sized toiletries.

Despite occasional political promises to scrap the rule, security agencies argued for years that legacy X-ray systems could not reliably distinguish between harmless liquids and those that might pose a threat. As a result, the restriction remained in place even as other elements of aviation security evolved.

The turning point came with the maturation of computed tomography scanners capable of rendering detailed 3D images, similar to medical CT equipment. These machines allow operators to rotate and inspect the contents of a bag virtually, applying sophisticated algorithms to flag anomalies, including suspicious liquids, with far greater accuracy than older systems.

The capital cost of installing the machines, reconfiguring security halls to accommodate their size and weight, and training staff created a high barrier to rapid adoption. That, combined with pandemic-era pressures on airport finances and international supply chains, explains why the rule has only now been fully lifted at Heathrow and Gatwick, nearly two decades after it was first imposed.

Travel Advice: Check Rules at Both Ends of Your Journey

While the end of the 100 millilitre rule in London is a relief for many, travel experts are warning passengers not to assume that the same freedoms apply at every airport on their itinerary. Many UK regional airports and a significant number of international hubs still enforce the traditional liquid limits or are in the early stages of upgrading their security equipment.

That means a traveller departing from Heathrow or Gatwick with large liquid containers in their hand baggage could still run into problems when leaving another country or transiting through an airport that has not yet changed its rules. In such cases, items that were allowed out of London may be confiscated on the return leg or at a transfer point.

Airlines and airports are advising passengers to check the latest security guidance not only for their departure point but also for their destination and any intermediate stops. This is particularly important for itineraries involving tight connections, where unexpected secondary screening could increase the risk of missed flights.

Frequent flyers and travel agents say that for complex journeys, especially those passing through smaller airports or regions slower to adopt new scanners, it may still be prudent to pack larger liquid containers in checked baggage. For straightforward trips in and out of Heathrow or Gatwick, however, the long era of the 100 millilitre limit is finally over, reshaping how Londoners and visiting tourists pack their bags for the airport.