Just linking this so people do not have to search for it:
Travelling to the UK from outside the European Union (EU)
When travelling from a non-EU country (including the Canary Islands, the Channel islands and Gibraltar) you can bring the following into the UK for your own use without paying UK tax or duty:
200 cigarettes; or 100 cigarillos; or 50 cigars; or 250g of tobacco
60cc of perfume
2 litres of still table wine
250cc of eau de toilette
1 litre of spirits or strong liqueurs over 22 per cent volume; or 2 litres of fortified wine*, sparkling wine or other liqueurs *such as port or sherry and
£145 worth of all other goods including gifts and souvenirs.
If you have any more than these allowances you must declare the goods in the red channel or use the red point phone. If you do not, you are breaking the law and we may prosecute you.
If you are under 17 you cannot have the tobacco and alcohol allowances.
You are entitled to these allowances only if you travel with the goods and do not sell them.
If you bring in something worth more than the limit of £145, you must pay charges on the full value, not just the value above £145.
You and anyone you are travelling with cannot pool your individual allowances to bring in an item worth more than the limit. You will have to pay charges on the full value of the item.
If you are bringing back any duty-free or tax-free goods you bought when you left the UK, these count as part of your allowance.
If you also have tobacco or alcohol goods that you bought in an EU country (other than tobacco products over the limit for imports from that country) you will not have to pay any more duty or tax on these so long as:
they are for your own use and
you can show, if we ask you to, that you have paid duty and tax in an EU country, for example by producing the receipt.
If you are bringing your personal belongings or your car into the UK from outside the EU, see Notice 3. Bringing your belongings and private motor vehicle into the UK from outside the EC.
Air transfers. If you arrive by air and are transferring to a flight to another EU country, at the transfer point you need only declare goods in your hand baggage. You do not declare your hold baggage until you collect it at your final destination.
The same usually applies if you are transferring to a UK domestic flight. But in some cases we must clear both your hand luggage and hold baggage at the transfer airport. The airline will tell you when this is necessary.