Best way to replenish currency in Ireland & Scotland

There is no better way than using a debit card at ATMs. But when you alert your bank that you will be away, also ask them to raise your daily cash withdrawal limit. Some are automatically set as low as $300, which would probably have you visiting a cash machine every day and might not even be enough.

You "think" you can use your bank cards? You should be SURE you can use your ATM/Debit cards to withdraw cash or you could be in a very bad situation.

Thanks for both replies. I'm definitely going to make sure that the bank card I have will be acceptable in europe.

Just make sure that your debit card has a 4 digit pin. Most of them do but it's good to verify that before you depart on your trip.
Per Laura, make sure that you inform your bank (for the debit card) and your credit card company about your travel plans lest they place a hold on your card for possible fraudulent activity. Can then be a hassle to contact them from overseas and sort everything out (ask me how I know this).

Note that there can be two different cash limits on ATM withdrawals. The first is the daily limit that your financial institution imposes. That daily limit can be raised to a higher amount but would require discussion with your financial institution.

The second ATM withdrawal limit is that imposed by the ATM owner. The machine limit is independent of your daily limit.

PS If you are dependent on cash, you should consider a second card from a secondary financial institution because situations happen.

Northern Ireland banks' sterling banknotes are not always accepted by people in Scotland and vice versa. You might not have an issue but to be on the safe side try to avoid this scenario.

i got a schwab debit card to only use in Europe. No exchange fees and if you are charged for using an ATM machine they reimburse the fee (was only $3 per use but free is better) Had no issues with it in Italy or Scotland. I have no stake in schwab just heard it was good deal and it was!

Marco's note that "Northern Ireland banks' sterling banknotes are not always accepted by people in Scotland and vice versa" is a quirk that we ran into last year in NI. A local couple at a pub in Bangor noticed me looking at the bills I received in change. They assured us that the bills were "perfectly OK, but they may not like them in England". If I recall correctly, they stated that each different part of the UK prints its own banknotes, but they all use the same coins. It might be educational for the rest of us to get a tutorial from Marco or one of our other UK friends on this interesting subject. In my case since we don't expect to be in NI again for some time, I was motivated to get rid of my excess NI pounds ASAP, even at a sizable loss in the exchange.

Private banks have always been issuers of bank notes in the UK - even the Bank of England was a private bank until 1946.

Note issuers are:

England & Wales: Bank of England
Scotland: Bank of Scotland, Royal Bank of Scotland, Clydesdale Bank
Northern Ireland: Bank of Ireland, First Trust Bank, Ulster Bank, Danske Bank / Northern Bank

You can't just set up shop and print your own notes - these are successors to banks that were issuing in the 1840s when various acts were passed.

Now these days Scottish notes of £20 denomination or less can be spent fairly easily in England (Clydesdale ones can take a second look) but the ones from Northern Ireland can cause problems in Great Britain if anything because of the confusion of two of the banks looking like they are from a different country. There isn't a real problem for locals as banks will take them as deposits into accounts but some may take some convincing.

At ports and airports you may find ATMs containing Bank of England notes for people leaving Northern Ireland, signed as such.

The situation is different again with sterling notes issued by the Isle of Man, Jersey, Guernsey, and Gibraltar governments. There the advice is to exchange before leaving.