I’m a South African travelling from the USA to South Africa via London. Will I need a visa or something even if I don’t go out of the airport?
With a South African passport, coming from the US, this is what you would find:
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.
You won’t need a visa if you:
- are travelling to Canada, New Zealand or the USA and have a valid visa for that country
- are travelling from Canada, New Zealand or the USA and it’s less than 6 months since you last entered that country with a valid entry visa
So, when did you last travel to the US? What your US visa valid at the time? If the time is 6 months or less and it was a valid visa, you're fine. Anything else, get a DATV.