I am a pakistani citizen. I am travelling to Canada via London on British Airways and Air Canada.
I know I will have to change terminals at heathrow. I do however have a valid visit visa to canada and usa. I will have my baggage checked all the way to canada aswell.
I know there is an internal train within heathrow that would allow me to change terminals without crossing immigration.
I still want to know do I need a visa to change terminals such as DATV or would i be exempted from the visa requirement.