Shimbleshanks
Established Member
There's a precedent closer to home. Ireland had a separate currency from 1928 (the Irish Pound, or punt) but for over 50 years it was tied to Sterling, until Ireland decided to joining the ERM.
This meant that Ireland effectively had to decimalise at the same time as the UK. I guess it meant that it was difficult for Ireland to follow a different interest-rate policy to the UK, at least without strict currency controls.
Incidentally, there is still a similar situation today with Channel Islands currency, which is denominated in Pounds and Pence with physically similar-sized coinage but is not legal tender outside the islands. (In the days when I used to travel regularly to the Channel islands in the 1980s and early 1990s one of the few places in the UK I could get to accept it was the ticket window at Waterloo station.)
I suppose there's no reason why the Scots couldn't have a 'Scottish Pound' that would be tied to Sterling but wouldn't be legal tender south of Gretna Green - and very possibly nothing the English government could do to stop them.
As an aside, I grew up on Anglesey, where the Irish Sea Port of Holyhead was situated and Irish coins (though not notes) certainly were accepted there in the 1960s and 1970s; it may have been an unofficial arrangement. I remember my parents having to sort through their loose change to get rid of any Irish money before venturing onto the mainland at Bangor or beyond for shopping trips - though not when going to Liverpool where there was a similar arrangement. That came to an end when the Pound was 'floated' on the money markets and the tie between the Irish currency and Sterling was ended.