What is customs control?

Customs control or immigration control?

Immigration control is about people: it decides the terms on which a traveller may enter a country. Customs control is about goods: it decides what may come in and on what conditions. Because both are usually cleared on arrival, travellers often treat them as one step, even though a traveller can be admitted at immigration and still owe duty on what is in the suitcase. The people side of the border, including the automated gates used at some airports, is covered under entry permission types and e-gates.

The scope of customs work is set out by each authority. HM Revenue and Customs (HMRC), the UK tax authority, says travellers must declare goods that go over their allowances and goods that are banned or restricted before crossing the UK border [1]. U.S. Customs and Border Protection (CBP) describes customs duty as a tariff or tax imposed on goods when they are transported across international borders, aimed at protecting each country's economy, residents, jobs and environment by controlling the flow of goods, especially restrictive and prohibited goods, into and out of the country [2].

How do you declare goods at customs?

Under UK rules, all commercial goods must be declared, and there are no personal allowances for goods brought in to sell or to use in a business [1]. A declaration can be made online from 5 days (120 hours) before the traveller is due to arrive in the UK [1]. Goods and any vehicle used to transport them may be seized if the rules are broken, and a traveller may also be fined or prosecuted [1].

In the United States, the test is whether the goods are new to the traveller: anything brought back that was not held when leaving the country must be declared. CBP's own examples are alterations made in a foreign country to a suit the traveller already owned and gifts acquired outside the United States [2]. American Goods Returned (AGR) are the exception — they do not have to be declared, but the traveller must be ready to prove to CBP that the articles are AGR or pay customs duty [2].

Families get one practical relief in the United States. A joint declaration can be made by family members who live in the same household and return together, and they can combine their purchases to use a combined flat duty rate no matter which family member owns a given item; CBP's illustration is a family of four travelling together, whose combined value of merchandise subject to a flat duty rate would be $4,000 [2]. Purchase totals must be rounded to the nearest dollar [2].

What duty or tax follows a declaration?

For U.S. entries, each article has a specific duty rate, fixed by factors that include where the article was acquired, where it was made and what it is made of [2]. The rate itself is a percentage determined by the total purchased value of the article paid in the foreign country, and not by factors such as quality, size or weight; CBP takes the applicable rates and statistical categories from the Harmonized Tariff Schedule of the United States Annotated (HTSUS) [2].

Two traps sit outside the headline allowance. First, a flat duty rate applies to articles that are dutiable but cannot be included in the personal exemption, even if the traveller has not exceeded that exemption at all — CBP gives alcoholic beverages as the example [2]. Second, in the UK, going over an allowance means paying tax and duty on all the goods in that category rather than on the amount above the limit [1].

Buying in a duty-free shop does not settle the customs question. CBP says duty-free shop articles are free only for the country in which that shop is located, so articles bought in a duty-free shop, whether in the United States or abroad, are subject to customs duty on entering the destination country if they exceed that country's personal exemption or allowance; purchases made in an American duty-free shop are also subject to U.S. customs duty if brought back into the United States [2]. In the UK, the personal allowance applies to goods bought overseas wherever they were bought, including in a duty-free or tax-free shop [1]. Refunds of consumption tax on shopping are a separate matter and are covered under VAT refund.

Exceptions, allowances and limits

Allowance figures are national, not universal, and they are quoted here only from the named authority as of 18 October 2026. For the UK, HMRC says the amount that can be brought in without paying tax or duty depends on where the traveller is travelling from and on whether they are arriving in Great Britain (England, Wales and Scotland) or in Northern Ireland, so there is no single UK number [1]. The limits themselves are set out on the duty-free allowance page.

• U.S. returning resident example. CBP gives the case of a returning resident eligible for the $800 duty-free personal exemption every 31 days, having remained no less than 48 hours beyond the territorial limits of the United States; that exemption includes no more than 200 cigarettes and 100 cigars [2].
• Alcohol. One American litre (33.8 fl. oz.) of alcoholic beverages may be included in a returning resident's personal exemption if the traveller is at least 21 years old, the alcohol is intended exclusively for personal use and not for sale, and it does not violate the law of the state of arrival [2]. Federal and state regulations allow one litre duty-free; a state may permit more, in which case the applicable customs duty and Internal Revenue Tax are payable [2].
• Household effects. Household effects may be imported duty-free if they were used abroad for no less than one year and are not intended for another person or for sale, but clothing, jewellery, photography equipment, portable radios and vehicles are treated as personal effects and cannot be brought in duty-free as household effects; all vehicles are dutiable [2].
• Paying. Any customs duty owed in the United States must be paid before the conclusion of CBP processing, in U.S. currency, by personal check in the exact amount drawn on a U.S. bank, or by government check, money order or traveller's check within the stated margin, with MasterCard or VISA accepted at some locations [2].

Frequently asked questions

Is customs the same as immigration?

No. Customs control deals with goods and the duty or tax they attract — in the UK you must declare goods above your allowances and any banned or restricted goods before crossing the border [1] — while immigration control decides whether and on what terms a person may enter.

Do you have to declare things you already owned before the trip?

In the United States, yes, if the item changed while you were away: CBP says anything brought back that you did not have when you left must be declared, and cites alterations made abroad to a suit you already owned [2]. American Goods Returned are the exception, provided the traveller can prove the status to CBP [2].

Are goods bought in a duty-free shop exempt from customs duty?

No. CBP says duty-free shop articles are free only for the country where the shop is located, and become subject to customs duty on entering the destination country if they exceed the personal exemption or allowance [2].

How much can you bring into the UK before paying tax or duty?

There is no single figure: HMRC says the amount depends on where you are travelling from and whether you arrive in Great Britain or Northern Ireland [1]. Current limits belong on the duty-free allowance page.

When can you submit a UK customs declaration?

Goods can be declared online from 5 days (120 hours) before the traveller is due to arrive in the UK [1].

Related pages

Terms: duty-free allowance, VAT refund, entry permission types, e-gates. Browse the full glossary of frequent flyer terms.

Sources

Sources accessed on 18 October 2026. Only UK rules from HM Revenue and Customs and U.S. rules from U.S. Customs and Border Protection are described here; the customs rules of the European Union and of other countries are not covered.

1. GOV.UK, Bringing goods into the UK for personal use (HM Revenue and Customs), checked 18 October 2026
2. U.S. Customs and Border Protection, Customs Duty Information, checked 18 October 2026