You’ll need a visa to pass through the UK in transit (unless you’re exempt)
You should apply for a Direct Airside Transit visa if you arrive in the UK on a flight and leave again without passing through immigration control.
Exemptions
You don’t need a visa if you have one of the following:
a visa for Canada, New Zealand, Australia or the USA (this can be used for travel to any country)
a residence permit issued by Australia or New Zealand
a common format residence permit issued by an European Economic Area (EEA) country or Switzerland
a resident permit issued by Canada after 28 June 2002
a uniform format category D visa for entry into a country in the European Economic Area (EEA) or Switzerland
an Irish biometric visa (marked ‘BC’ or ‘BC BIVS’ in the ‘Remarks’ section)
a Schengen Approved Destination Scheme (ADS) group tourism visa where the holder is travelling to the Schengen country that issued the visa
a flight ticket from the Schengen area, if you can prove that you entered the Schengen area in the previous 30 days on the basis of a valid Schengen ADS visa
a valid USA I-551 Temporary Immigrant visa issued by the USA (a wet-ink stamp version will not be accepted)
a valid USA permanent residence card issued by the USA on or after 21 April 1998
an expired USA I-551 Permanent Residence card issued by the USA on or after 21 April 1998, with a valid I-797 letter authorising extension
a valid standalone US Immigration Form 155A/155B issued by the USA (attached to a sealed brown envelope)
All visas and residence permits must be valid.
