Scotland, as part of the United Kingdom, operates on the Pound Sterling (£). Paying for expenditures in Scotland is very much like paying for them here. Most businesses accept credit cards, debit cards (associated with Visa or Mastercard), or cash. All transactions, whether Debit, Credit, or Cash are subject to exchange rates and possibly fees.
Credit cards: you should check and see if your credit card charges a foreign transaction fee and how they calculate the exchange rate. The most commonly accepted are Visa and MasterCard with AEX at major chains.
Debit Card: similar to credit cards, you should check to see if your bank charges a foreign transaction fee in addition to the exchange rate, You should also find out how the exchange rate is calculated.
In terms of cash, We recommend that your approach to carrying cash mirrors what you practice here. If you do not carry a lot of cash here, there is no need to do so in Scotland. To the extent that you want to have cash available, you will most likely get the most favorable exchange at your bank. Your local bank branch may need to order some £’s to accommodate your needs. It will probably charge a reasonable fee in addition to whatever exchange rate applies at the time. I strongly urge you to avoid using money changing services such as Travelex that are located at airports. It is my view that their fees are predatory. Just like here in the US, ATM’s are easy to find. There will be one at the Edinburgh airport just outside the international arrivals exit door (see below)
Additionally, there are generally ATM's at the hotels near to the front desk. The fee’s for using an ATM in Scotland are similar to what they are in the US: in many cases they are free and usually they are less than in the US. You will of course still be subject to what your bank may charge for a foreign transaction but you will most likely receive a reasonable exchange rate.