In article , owain41276
@stirlingcity.co.uk says...

So what if someone buys adjoining properties, one in England and one in
Scotland, and merges them, or builds across the border? The international
boundary doesn't move because someone puts a shed over it.

Council borders can, though. When the Braehead shopping centre opened,
it lay partly in Glasgow and partly in Renfrewshire - the Sainsbury's
store straddled the border, so they had to get off-licences from both
licensing boards. They've since shifted the border so the whole centre
is in Glasgow.

There are many properties (generally larger farms/estates) which
straddle county boundaries within Scotland, and those have to be
registered separately in each registration county. I suspect there will
be some which cross the English border, and the same principle will
apply.

David