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Security is the part of the trip most people dread. At Heathrow, it’s easier than it used to be.
The old routine of measuring bottles, bagging them up and unpacking your laptop has changed. This guide covers what you can pack, what still trips people up, and how to get through quickly.
At Heathrow security, you can keep liquids in containers of up to 2 litres each inside your cabin bag, and leave laptops and tablets in your bag too. You don’t need a clear plastic bag. Empty any metal or insulated bottle before you reach the scanner, take up to two pieces of hand baggage, and empty your pockets into a tray. The rules apply in Terminals 2, 3, 4 and 5.
Rules in this guide were checked against Heathrow’s official hand baggage and liquids page on 25 October 2026. Security rules can change, so check Heathrow’s website before you travel.
What Changed at Heathrow Security
Heathrow finished upgrading its security lanes to new CT scanners in January 2026. These scanners give staff a detailed 3D image of your bag, so there’s less need to unpack.
The result: the long-running 100ml liquids limit no longer applies when you fly out of Heathrow.
If you’ve read older guides that mention the 100ml rule or taking your laptop out of your bag, they’re out of date.
Heathrow Security Rules at a Glance
| Item | What to Do |
|---|---|
| Liquids, gels and pastes | Containers up to 2 litres can stay in your cabin bag; no clear plastic bag needed |
| Laptops and tablets | Leave them in your bag, and make sure they’re charged |
| Metal or insulated bottles | Empty them before security; refill once you’re through |
| Hand baggage | Up to two items, each no larger than 56cm × 45cm × 25cm |
| Pockets, coats and small items | Put coins, keys and phones in the tray; coats go in a tray if you’re asked |
| Pushchairs and walking aids | They will be screened |
Liquids at Heathrow Security
This is where most of the confusion sits, so let’s keep it simple.
What You Can Carry
You can carry liquids, gels, pastes and aerosols in containers of up to 2 litres. That covers drinks, toiletries, creams and perfume. You don’t need to bag them separately or take them out.
Baby Milk and Breast Milk
Heathrow allows baby food, formula milk and breast milk in your cabin bag. Breast milk comes with a few specific rules:
- It can be carried even if you’re travelling without your baby
- It must be liquid, not frozen
- Containers must be up to 2 litres
- It should be stored in a clear container or a commercially available storage bag
- Metal or insulated containers aren’t permitted
Formula, baby food and sterilised water have separate guidance, and your airline may add its own rules. Check Heathrow’s baby food and milk guidance and your airline before you fly.
Medicines
Liquid medicines can go in your cabin bag. If you need more than 2 litres during your journey, bring a prescription or a letter from your doctor confirming the medicine is needed for your flight. Pack any medicine you won’t need on the journey in your hold bag.
Travelling with specialist medication, medical equipment or sharps? Check with your airline in advance. Heathrow has a page on medication and equipment.
Duty-Free and Airport Purchases
You can usually take liquids bought after security onto your flight, including drinks, fragrances and cosmetics over 100ml. Some destinations have additional restrictions, though. For example, liquids over 100ml can’t be taken on flights to Australia, and powders over 350g or 350ml aren’t allowed in cabin bags on flights to the US.
If you buy powders or liquids after security, keep them sealed in a security tamper-evident bag with your proof of purchase. Unsure? Ask your airline or the shop assistant before you buy.
The Return-Journey Trap
Here’s what catches people out. Heathrow’s 2-litre rule only covers flights leaving Heathrow.
| Situation | Liquid Rule | Tip |
|---|---|---|
| Flying out of Heathrow | Containers up to 2 litres | Same rule in Terminals 2, 3, 4 and 5 |
| Flying back from another airport | Many airports still have a 100ml limit | Check your return airport’s rules before packing |
| Returning to Heathrow the same day | Your destination airport’s rules may apply | Ask staff before buying liquids you plan to bring home |
What You Can’t Take Through Security
Not every banned item is banned everywhere. It helps to split the list into three groups.
Banned From Hand Baggage
These aren’t allowed in your cabin bag. Heathrow’s lists include:
- Knives with blades over 6cm and razor blades
- Box cutters, and scissors with blades over 6cm
- Axes, hatchets, ice axes and swords
- Firearms, replica and toy guns, airguns, bows and slingshots
- Baseball bats, clubs and batons
- Stun guns, pepper spray, tear gas and similar sprays
The lists aren’t exhaustive, and security staff can refuse any item they believe is unsafe.
Tools: Hold Baggage Only
Tools such as drills, saws, crowbars and blowtorches must be packed in your hold baggage. So must screwdrivers or chisels with a blade or shaft longer than 6cm.
Dangerous Goods: Banned From Both Bags
Some items can’t travel in your hand baggage or your hold baggage. Heathrow lists:
- Explosives and fireworks
- Ammunition
- Grenades and replica explosive devices
- Flammable gases and liquids
- Toxic or corrosive substances
- Lighter fluid and firelighters
You can carry one cigarette lighter per person. For the full picture, see Heathrow’s banned and restricted items page and the GOV.UK hand luggage restrictions page.
Expert tip: If you’re unsure about something, check with your airline first. It’s easier than losing it at the lane.
How Early to Arrive
There’s no single right answer. Your airline sets its own check-in and bag drop cut-offs, and these differ by route.
As a rough guide, many airlines suggest about two hours before short-haul flights and three hours before long-haul. Follow your airline’s advice, especially at busy times like early mornings and school holidays.
Keep an eye on live security waits before you leave home. Heathrow publishes queue information on its website.
If you’re leaving later in the day or travelling with family, a pre-booked Heathrow airport taxi means you won’t be rushing through traffic. Flight monitoring helps if your plans change.
Fast Track Security at Heathrow
Heathrow offers a paid Fast Track service that gets you into a shorter queue. The rules inside the lane are the same, so you’ll still need to follow the same packing guidance.
Prices and availability change, so check Heathrow’s website before you book. For many travellers, good preparation saves more time than paying for a shortcut.
Tips for Getting Through Faster
- Pack for the scanner. Keep liquids and electronics easy to reach in case staff ask to take another look.
- Empty your pockets first. Do it before you join the queue.
- Wear easy shoes and layers. Coats may need to go in the tray.
- Charge your devices. If a device can’t be switched on during screening, you may not be able to take it on board.
- Keep it to two bags. Heathrow runs a two-bag policy at security.
- Pack food and powders in your hold bag if you can. They can slow down X-ray screening.
- Have your boarding pass ready. Download it before you leave.
Flying from a specific terminal? See our guide to Heathrow Terminal 2 for layout and check-in tips.
Common Mistakes at Heathrow Security
- Trusting old rules. Many older guides still mention the 100ml limit.
- Forgetting to empty metal bottles. They must be empty before the scanner.
- Packing too much in hand baggage. More than two items slows you down.
- Assuming the same rules apply on your return flight. Always check the other airport.
- Arriving without travel documents. Many visitors need a UK ETA before flying, so read our UK Electronic Travel Authorisation guide or the official GOV.UK ETA page.
Arriving at Heathrow With Less Stress
Security goes more smoothly when your journey to the airport does. A fixed-price transfer takes traffic and parking off your list, and it’s worth considering if you’re travelling with heavy bags or small children. We cover all four terminals: Terminal 2, Terminal 3, Terminal 4 and Terminal 5.
Frequently Asked Questions
Can I take liquids through Heathrow security?
Yes. Containers of up to 2 litres each can stay in your cabin bag at all four terminals. You don’t need a clear plastic bag.
Do I need to take my laptop out at Heathrow security?
No. Heathrow’s scanners let you keep laptops, tablets and other large electronics in your bag. Keep them charged, as a device that can’t be switched on may not be allowed on board.
Is the 100ml liquid rule still in force at Heathrow?
No. It no longer applies to flights leaving Heathrow. Many other airports still use it, including on your return journey, so check the rules there.
Can I take a metal water bottle through Heathrow security?
Yes, but it must be empty. Reusable metal and insulated bottles need to be emptied before security, and you can refill them afterwards.
How many bags can I take through Heathrow security?
Up to two items of hand baggage. Each should be no larger than 56cm × 45cm × 25cm. Check your airline’s own allowance too, as limits vary.
Can I take medicine through Heathrow security?
Yes. Liquid medicines can go in your cabin bag. If you need more than 2 litres for your journey, bring a prescription or a doctor’s letter. For specialist medication, equipment or sharps, check with your airline before you travel.
Can I take baby milk and breast milk through Heathrow security?
Yes. Breast milk must be liquid (not frozen), in containers of up to 2 litres, and stored in a clear container or commercially available storage bag. Metal or insulated containers aren’t permitted. Formula and baby food have separate guidance, so check Heathrow’s page and your airline.
Can I take duty-free liquids on my flight?
Usually, yes, if you buy them after security and keep them sealed with your receipt. Some destinations add their own restrictions, so check before you buy, especially for flights to Australia or the US.
How early should I arrive for my flight at Heathrow?
Follow your airline’s advice, as check-in and bag drop times differ. Many airlines suggest around two hours for short-haul and three hours for long-haul, and extra time at busy periods.
