Prior to the UK's exit from the EU, trade between the UK and Crown Dependencies was governed by protocol 3 of the UK's EU accession treaty.[9]
On 26 November 2018, the UK signed customs agreements with each of the Crown Dependencies to allow free trade to continue to flow across between all the parties by creating a single UK–Crown Dependencies Customs Union.[10]
On 29 December 2020, the UK–Crown Dependencies Customs Agreements took effect and officially created a customs union between the UK and Crown Dependencies.[11]
Though Northern Ireland is considered an integral part of the United Kingdom and is not part of the European Union, to maintain a peaceful resolution of the Northern Ireland Conflict, it has an open border with the Republic of Ireland, which is part of the European Union single market. The Northern Ireland Protocol, which first came into effect on 24 March 2023, regulates inter-island trade to support this arrangement. Internal shipments from Great Britain to Northern Ireland are regulated as imports to the EU, but shipments from Northern Ireland can enter the rest of UK customs union barrier-free.
On 26 September 2023, the UK Treasury made The Customs (Northern Ireland) (EU Exit) (Amendment) Regulations 2023. This is a statutory instrument (2023 No. 958) The new regulations updated the UK's customs duty rules for goods moving between Great Britain and Northern Ireland and created a wider definition to determine whether food is at risk of entering the EU.[12]
These agreements also state that they may be terminated at any time by mutual agreement.[14]
Common Transit Convention
On 29 December 2020, the United Kingdom became an independent member of Common Transit Convention; this has been extended to the crown dependencies through the UK–Crown Dependencies customs union and is used as the basis for common transit between members.[15]
Customs alignment
Paragraphs 10 to 12 provide that members of the customs union will align with the UK in areas of customs laws, rules and procedures.[16]
Joint UK-CD Customs Committee
The customs agreements created a joint customs committee (UK-CD Customs Committee).[10] This committee will meet at least once a year and will act as a forum for:
Exchanging views on common interests regarding the agreements
Reviewing the operation of the agreements
Seeking appropriate way and methods to avoid problems occurring in regard to areas covered in the agreements
Mediation should problems occur regarding areas covered in the agreements.[11]
External Customs Tariffs
In 2020 the UK government passed the Customs (Tariff Quotas)(EU Exit) Regulations 2020. The purpose of this regulation is to update definitions in customs legislation.[17]
Customs agreements
Customs agreements, entered into force on 29 December 2020
^Although each of the dependencies signed an individual agreement with the UK, these agreements include provision for the inclusion of the other dependencies creating a single customs area between the members.[5]
Quantitative restrictions Article XI of the GATT 1994 is the main provision regulating quantitative restrictions (QRs). The scope of this provision includes all prohibitions or restrictions other than tariffs or other taxes applied or maintained by a WTO Member on the importation or exportation of goods, which can be made effective through quotas, import or export licensing procedures, or other measures. Although Article XI of the GATT provides for the general elimination of quantitative restrictions, they are allowed in certain specific circumstances. Members' QR notifications seek to provide transparency on these measures, including on its WTO justification.