Packing to the weight limit, and the security rules that decide the rest

Subtract the case before you pack anything

An allowance covers the bag and its contents. A hard cabin case weighing 2.6 kg inside a 10 kg allowance leaves 7.4 kg, and that is the number to pack against. Writing the empty weight on a label inside the lid means you never have to remember it at the moment it matters.

Once you have the real figure, pack heaviest first and weigh as you go rather than at the end. Shoes, a wash bag with full bottles and a laptop are the three items that consume an allowance fastest. A second pair of shoes at 800 g is about 11% of a 7.4 kg allowance, which is the clearest argument for wearing the heavier pair onto the aircraft.

Bathroom scales are accurate enough if you weigh yourself, then weigh yourself holding the case, and subtract. Do it twice and take the second reading, because the first is usually taken before the scales have settled.

The liquids rule, as GOV.UK states it

GOV.UK's hand luggage guidance states that at most airports you cannot take liquids in containers larger than 100ml through security, that containers must be in a single, transparent, resealable plastic bag which holds no more than a litre and measures approximately 20cm x 20cm, and that you are limited to one plastic bag per person.

There are defined exceptions. The same guidance says you can take liquid containers up to 2 litres through security at all UK airports if they are for essential medical purposes, if they contain baby food or baby milk, or if they are for special dietary requirements. It also notes that some airports may allow containers holding up to 2 litres of liquid generally, and that the rules have changed at some UK airports.

The practical consequence for packing is that the wash bag is a fixed-volume problem rather than a weight problem. One litre of bag, one bag, and every bottle 100ml or under. Decanting into 100ml bottles before you leave is a 10-minute job that removes the most common reason a cabin bag gets opened.

1. Containers of 100ml or less, at most airports
2. One transparent resealable bag per person, holding no more than a litre, about 20cm x 20cm
3. Up to 2 litres at all UK airports for essential medical purposes, baby food or baby milk, or special dietary requirements
4. Some airports may allow containers up to 2 litres more generally, and some have changed their rules
5. Countries outside the UK may apply different rules to transit and transfer passengers

Packing order, and what goes in the cabin regardless

Pack in three layers. The bottom layer is dense and flat: shoes sole-to-sole in a bag, jeans, anything with a hard edge. The middle layer is rolled soft clothing, which fills the gaps the first layer leaves. The top layer is what you want within reach at security: the liquids bag, the laptop and anything with a battery.

Some things never go in the hold whether or not the bag fits. Medication, documents, keys, chargers and anything you could not replace at the destination belong in the cabin, because a bag that goes astray typically does so for a few days rather than permanently, and those are the days you need them.

A packing list written once and kept on a phone is worth more than any packing technique. It takes about 15 minutes to write and it removes the two failure modes of every trip: taking something you did not need, and leaving behind the one thing you cannot buy on arrival.

If the bag comes back damaged, or does not come back

The CAA's passenger guidance sets out deadlines that are short and easy to miss. You must contact the airline in writing within seven days for lost or stolen items, or for damaged baggage, and within 21 days for a delayed bag, counted from receiving the delayed bag.

The CAA also says the maximum compensation is around £1,000, and notes that this would be very rare. It states that airlines do not allow for new for old replacement when considering the value of a claim, so a three-year-old case is valued as a three-year-old case. Keeping receipts, or at least photographs of the contents, is what turns a claim into a paid claim.

Report the problem before you leave the airport and keep a copy of the Property Irregularity Report that airline staff complete. The CAA notes that having a PIR is no guarantee the airline will accept your claim, but a claim without one starts from a worse position.

The ten minutes before you leave the house

Weigh the packed case. Open the liquids bag and confirm nothing in it is over 100ml. Move medication, documents and batteries into the cabin bag if they have drifted. Photograph the open case, which takes 30 seconds and is the evidence a claim needs if the bag is later damaged.

Those four actions take about 10 minutes and remove almost every version of this going wrong. None of them depends on which airline you are flying, which is why they are worth making a habit rather than a decision.

Before you buy

• Write the empty weight of the case on a label inside the lid
• Subtract it from the allowance and pack against the remainder
• Weigh the case on bathroom scales as you go, not at the end
• Decant liquids into 100ml containers and fit them in one 1-litre transparent bag
• Keep medication, documents, keys and batteries in the cabin regardless of space
• Photograph the packed case before you close it
• If a bag is damaged, write to the airline within 7 days; for a delayed bag, within 21 days of getting it back

Questions readers ask

Can I take a full-size bottle of sun cream in hand luggage?

Not at most airports. GOV.UK states that at most airports you cannot take liquids in containers larger than 100ml through security, and that the containers must fit in a single transparent resealable bag holding no more than a litre, one per person. Larger bottles go in the hold, or you buy at the destination. The defined exceptions are medical use, baby food or milk, and special dietary requirements.

How long do I have to report a damaged bag?

The CAA's guidance says you must contact the airline in writing within seven days for damaged baggage or for lost and stolen items, and within 21 days for a delayed bag counted from when you receive it. Report it at the airport and keep the Property Irregularity Report, although the CAA notes a PIR is no guarantee the claim will be accepted.

How much can I claim for lost contents?

The CAA puts the maximum at around £1,000 and says that figure would be very rare in practice. It also states that airlines do not allow new for old replacement, so items are valued at their age and condition. You have to demonstrate what the bag and contents were worth, which is why receipts, card records or photographs matter more than the headline limit.

Does wearing my heavy coat onto the plane actually help?

Yes, measurably. On a 7.4 kg contents allowance, moving an 800 g pair of shoes and a 600 g coat out of the case frees about 19% of the allowance. Whether an airline counts a worn coat towards hand baggage is set by the airline rather than by the security rules, and it is published with the booking conditions.

Should I lock a cabin bag?

A cabin bag stays with you, so a lock mainly deters opportunistic access in an overhead locker and on public transport. The bigger risk is a bag you are made to gate-check at short notice, at which point anything valuable should already have moved into a coat or a small shoulder bag. Pack so that the gate-check scenario does not need a decision.

Sources

1. GOV.UK — Hand luggage restrictions at UK airports: liquids (100ml containers, one 1-litre bag per person, 2-litre exceptions) — checked 2026-11-03
2. UK Civil Aviation Authority — Lost, delayed or damaged baggage (7 and 21 day deadlines, around £1,000 maximum, no new for old) — checked 2026-11-03
3. GOV.UK — Hand luggage restrictions at UK airports (overview) — checked 2026-11-03