Originally Posted by
LiviLion
I've found a considerable spanner in the works for my UA plan as I need to be able to access a US credit card to reserve a E+ seat at booking otherwise I've got to hope for a decent E+ seat at check-in which isn't going to happen as the seat map shows E+ seat on the side of the plane pretty much gone so expect them all to have gone bar the 5 in the middle which I don't really want.
Even if you book your main ticket on unitedairlines.co.uk, you can log into united.com later with your PNR and add Economy Plus separately. While united.com won't accept non-US cards for initial booking, they will accept them for "travel options".