Originally Posted by
etiene
That's because this is not a transit - it's across two tickets [not sure if there's an official term, some round here call it "self-connecting" or similar]. If BA let you on without you being able to enter the Netherlands they would get fined should you try to do so, as the contract for the first ticket is just to take you to the Netherlands and is not affected by the ex-EU. In the event that you do the same when on an actual transit [i.e. one ticket] I presume their defence is that they sold you a connecting ticket and it's not their fault you're trying to do something different.
Transit is a transit doesn't matter if it is on two seperate tickets, I just did it two days ago from MCO-CLT-JFK-LHR-AMS with the LHR- AMS being on a seperate ticket We had to pick up luggage re-check in so went landside. For the Dutch rules land or airside doesn't matter you can even transit by train/ boat under the dutch regulations as long as it is less than 12 hours.
Problem is other than the shear pettiness of the dutch government to have separate rules for the UK compared to as the rest of the planet. Is in our case the BA system could not deal with the fact we are transiting on separate tickets and the check in staff also are confused (not in our case)