Phil wrote

Yes. (Where "national" = England.)

---------------------------------------------------------------

Oops, I forgot that bit :-(

How does that work for cross border services?

I often see a bus in Shrewsbury with Llandiloes - Newtown - Welshpool
-
Shrewsbury on it. Am guessing it is a shopping link for rural Mid
Wales
into a large town, is it free as far as the border and then pay the
fare
from there?

I Googled [cross-border bus pass]

and found "People living in Wales can also use their passes to travel
free on cross-boundary journeys in and out of England, provided the
journey starts or finishes in Wales"

There are similar extensions for some journeys to Scotland that start
or finish in England to/from Northumberland or Carlisle. Examples
Newcastle-Jedburgh, Carlisle-Gretna


--
Mike D