Originally Posted by
chil
2. I'll be traveling with my colleague who has Russian passport and no British visa, so for him it's not an option to go outside in Heathrow. If he travels without checked bags, will he be able to re-check on the BA flight to Moscow on a BA transfer counter before clearing the customs? Will the existence of a separate LHR-DME ticket be a sufficient argument for him to be admitted on the airplane from EZE to LHR?
He can re-check for the flight to Moscow at the transfer counter, but that is not the problem.
Whether he would be allowed to board the flight from EZE to LHR is uncertain.
Russian citizens are not required to hold a Direct Airside Transit visa for the UK but are required to hold a Non-Direct Airside Transit visa. They might or might not allow your colleague to board on presentation of an onward ticket on the basis of treating it as a direct airside transit, but IMO it is not worth the risk of being denied boarding (given the large fines airlines face, who can blame them for erring on the side of caution?), so perhaps he should get a non-direct airside transit visa.
UK government website:
https://www.gov.uk/government/public...-transit-visas
Think about the potential consequences of denied boarding (expenses, how long it would take, etc. - visas are the individual traveller's responsibility so it's not very likely that the airlines would help much in this circumstance other than maybe to rebook them).