Are any nationalities excluded from the TWOV concession?
This concession does not apply to certain visa nationals who must have a visa to pass through the UK on their way to another country, even if they are not entering the UK or changing airports. This is known as a ‘direct airside transit’ visa (DATV). If you are a national of one of the countries in the link below, you will need to have a valid UK DATV: Direct Airside Transit Visa (DATV) Nationals If you have a DATV, you will not be able to pass through UK immigration control. You will not usually be allowed to stay in the UK overnight to wait for a connection to continue your journey. If you are a direct airside transit (DAT) national and passing through the UK on your way to or from the Republic of Ireland, the Channel Islands or the Isle of Man, you need a visit visa for the UK, unless you are exempt from the DAT requirement.