The legal basis is the Trade Marks Act (TMA) 1994.

Registration provides protection for the trademark in the United Kingdom (UK) of Great Britain and Northern Ireland and automatically extends to the British Indian Ocean Territory, the Falkland Islands, the Isle of Man, and South Georgia and the Sandwich Islands. In the Bahamas, subject to locally acquired prior rights, the owner of a UK trademark is entitled to registration on the production of a UK registration certificate.

Trademark protection is available in the following countries through the extension of an existing UK trademark registration: Gambia, Gibraltar, Jersey, Kiribati, Saint Helena and dependencies, Solomon Islands, and Tuvalu. With respect to Gambia, an application must be filed within 4 months of the UK application date in order to be afforded the UK filing date as a priority date.

In addition to local registration, it is also possible to apply for registration based on a UK trademark in the following countries: Anguilla, Bermuda, Fiji, Grenada, Guyana, Montserrat, Saint Kitts and Nevis, Saint Lucia, Samoa, and Sierra Leone. In Samoa, an application based on a UK trademark must be filed within 12 months of the UK application date.

From January 1, 2021, applicants and holders under the Madrid Protocol may designate the Bailiwick of Guernsey in international applications and in subsequent designations bearing a date of January 1, 2021, or later.

British territories with no trademark law and therefore no extension of UK rights include the Pitcairn Island and the British Antarctic Territory.

The UK is a member of the Madrid Protocol. The UK has left the European Union on February 1, 2020 (23:00 GMT on January 31, 2020).

From January 1, 2021, an address for service in the UK, Gibraltar, or the Channel Islands is required to file a new trademark application and to participate in new oppositions or other proceedings at the UK Intellectual Property Office (UKIPO).

On January 1, 2021, the UKIPO created comparable UK trademarks for all registered EU trademarks. These comparable trademarks retain the same filing date as the corresponding EU trademark, including any priority and seniority dates. The numbers for these comparable UK trademarks of EU trademarks have the prefix ‘UK009’. The UKIPO also created comparable UK trademarks for all protected EU designations of WIPO international registration. The filing and registration date of the comparable UK trademark corresponds to the date on which protection in the EU was conferred. The numbers for these comparable UK trademarks have the prefix ‘UK008’.

Trademark protection is obtained by registration. It can also be acquired by use.
The UK is a common law jurisdiction, i.e., official and juridical decisions on the Trade Marks Act 1994 are rendered on the basis of prior decisions and judgments in similar cases.