[Studio25]

Just to be pedantic - the term "legal tender" has a very narrow definition, and it's for legal reasons: Basically it's the currency which has to be offered by a debtor for their debt to be considered legally satisfied. If you owe someone a fiver, and offer them a bottle of wine in repayment, they can choose to accept (or not). If you offer a fiver, they have no choice. If they refuse, the debt is still considered legally settled.

Note that for most retail transactions, there is no debt at the point of sale, so you have to accept the use of whatever prevailing currency is used - and it doesn't have to be legal tender.

At petrol stations, restaurants, photography studios etc - you are usually settling a debt, so whatever the local "legal tender" is - it has to be accepted. Other locally used denominations may also be acceptable, but that's not enshrined in law.

Scotland and Northern Ireland do not have any legal tender banknotes. Bank of Scotland, Royal Bank of Scotland, Clydesdale Bank, Northern Ireland, Bank of Ireland, First Trust, Danske Bank and Ulster Bank notes are not legal tender anywhere.

In England and Wales, Bank of England notes are all legal tender. Throughout Great Britain and Northern Ireland, coins are legal tender, with a 20p limit for 1p and 2p coins, $5 limit for 5p and 10p coins and £20 limit for 20p and 50p coins. There's no limit on £1, £2 and £5 coins.

It leaves you in the situation where if you offer to pay for a restaurant meal in Scotland (or anywhere else in the UK) using pound coins, and they refuse, you can legally walk out as the debt is considered satisfied. In England and Wales, if you offer to pay using BofE notes, the same situation can arise but in Scotland, they can refuse.

Manx notes are legal tender on the Isle of Man, BofE notes aren't; but if you're likely to have a problem, you can freely exchange the notes at any bank when over there, and change them back at any English bank when you're home.

Apart from that, you can use whatever you want, anywhere in the UK - as long as the retailer is happy to accept them. The practical problem of accepting a Scottish retail-bank note (for example) is that its use is not intuitive in England and Wales, so it's harder for your typical retailer to spot if it's a forgery. Any notes that are backed by a stockpile of sterling currency will be exchanged at any bank.

So for cash transactions in the Isle Of Man, you could go to a bank on your first day and swap sterling for Manx notes, then when you're back here, go to the post office or bank and swap them back. As far as I can tell, it's not a currency exchange, so there should be no commission.