Currencies in the British Isles

I will be taking a trip to Ireland, Scotland and England in July and August. All 3 countries use different currencies. I plan on using my credit card for whatever I can but I’ve read that I will need to have a small amount of currency for little things. I’m not sure how to go about getting these currencies. I’ve been told I can get from a local bank before I leave home and from an ATM while over there. I don’t own a debit card and don’t want to get cash from my credit card because of the fees. What’s the best option? Do I really need to get Scottish AND British pounds or will having just British pounds work for the UK.I know I still need to get Euros for Ireland.
Thanks for any help!

I was there a long time ago, but they accepted Pounds with “Bank of England” printed on them in Scotland, and the other way around. The Scottish Pounds said “Bank of Scotland”. But interchangeable. I don’t know if it has changed, I hope not.

Thank you ochotona!

The official currency of England, Wales, Scotland, and Northern Ireland is the pound sterling

Figure out how much cash you believe you will need, double that, and take that much in dollars. You will be able to exchange dollars as you need them for the local currency at most banks (also at the airport, but that tends to cost more).

Or consider getting an ATM card just for your trip. You could set up a separate account with funds just for the trip, and not linked to your main accounts.