Dual nationals will be denied entry to the United Kingdom from 25 February unless they travel on a valid British passport, under new measures confirmed by the Home Office.

The change formalises long-standing guidance that British citizens, including those holding another nationality, must present British documentation when entering the country.

Officials said the updated enforcement approach is designed to ensure clarity at the border and to strengthen the integrity of immigration controls.

From the implementation date, individuals who are British citizens but attempt to enter using a foreign passport alone may be refused boarding by airlines or denied entry on arrival.

The government maintains that British citizens have the right of abode in the UK but must prove that status with appropriate documentation.

A British passport remains the primary evidence of citizenship and right to enter.

Those without one are advised to apply in advance of travel to avoid disruption.

The move is expected to affect thousands of dual nationals who have previously relied on non-UK passports when travelling.

Travel operators and airlines have begun issuing guidance to customers, and immigration advisers have urged affected individuals to check documentation well before departure.

Home Office representatives stated that the policy ensures consistent application of entry requirements and reduces ambiguity in border processing, emphasising that it does not alter citizenship rights but clarifies the documentation required to exercise them.