That is correct. The application to register to vote would be tied to the constituency in which the person was last registered or resident. It should not be possible for any individual to say, “Right, I pick that one”.
I have told the House how much it costs to process overseas voters’ applications to register. There are also additional costs, comparatively speaking, associated with overseas electors taking part in polls, and that again is due to things like international postage, where the average cost is again a little higher than it is for domestic voters.