Upvote:2
April 28, 2018 - May 2, 2018
Do I need a transit visa to get into London?
No, You need a standard visitor visa for that long a transit.
Apply for a Visitor in Transit visa if you’ll be going through UK border control but leaving the UK within 48 hours
However if your stay in the UK was for less than 48 hours and given the fact that you hold a visa for and are travelling to the USA you were eligible for a transit without a visa