Originally Posted by orbitmic

BA will let you change the flight to the nonstop and in the same travel class (if available) no issue - however I’d fully expect this to be considered a voluntary change subject to change fee and fare difference if applicable. It will be more comfortable but may also prove expensive.

it’s good the MK staff reassured you. To be honest, in my experience, small airlines are a lot more relaxed about separate tickets itineraries than large ones because it happens a lot with them due to the obvious limitations to their networks so I’m not surprised they felt it was an obviously fine case and Ba did not.

having said that, had it been me, after talking to them and getting their reassurance I’d have asked the person if it was possible to add a note in the booking “just in case”. That way, if the agent your wife deals with on the day is less helpful they could see you had already discussed it.