How much cash would you recommend for 13 day tour?

Here is what RS says on the tour FAQ section

https://www.ricksteves.com/travel-help/tours-faq

How much money will I need?
On fully guided tours, plan to spend between $50 and $100 per day for your beverages at group dinners, meals on your own, snacks, souvenirs, and free-time transportation and entrance fees.
For My Way tours you'll be responsible for the cost of all your lunches, dinners, and daily expenses — so your out-of-pocket expenses will likely be higher than on a fully guided tour. Be sure to plan and budget accordingly.

From my experience, you will not need much cash as you will be able to pay for almost everything with your credit card. You should be able to withdraw cash at an ATM while in Scotland. If you prefer to have GBP before you arrive, you can order from a bank or AAA at home.

I’d wouldn’t take more than £50 and that’s more than you should need. Almost every place is contactless payment. Cash is handy for small purchases.

On arrival find a ATM in town (not at the airport) and withdraw a hundred pounds or so and more as needed. If you want money on hand when you arrival, then use your local bank, local AAA, or your airport currency exchange for a hundred pounds. It will cost you about 6 to 10% in local fees but in the total picture it is not that big of an expense. I am old school and like have a hundred of something in my pocket on arrival and replace as need via local ATMS.

You will find it easy to spend less than £20 in cash. I am in Scotland for two weeks in May and don’t expect to use cash more often than I do in Cornwall, where I haven’t used cash in nearly 3 years.

I agree with Camborne2018 that 20GBP would probably be enough. 50GBP cash would be more than enough and give you seed money for next time.

Do you use ApplePay or GooglePay? Last August I was on Orkney and Shetland for 2 weeks and Aberdeen for a couple of nights and I used ApplePay everywhere. The only cash I used was to leave housekeeping in the hotel a tip. IF you haven't gotten in to using Apple/Google Pay I encourage you to start this at home so you are comfortable with it. Contactless payment is everywhere.

You do need to have room on your CCs to accommodate the charges for meals and other things you wish to purchase.

Last year, I spent about two months in Scotland. I only used cash for haircuts and taxis in Dundee. Everywhere else was either Google Pay or Credit card.

You won't need a lot of cash. But life will be easier if your credit cards are contactless or you set up Google Pay or Apple Pay on your phone depending on your device.

We spent 2 weeks in Scotland in 2022 and came across one B&B and one pub that was cash only. Other than that it was always credit card. Between the two I needed about £400. Plus often needed small change for washrooms. We spent cash at convenience stores for small purchases so we had change on hand.

Last summer I withdrew 50 GBP from an ATM upon arrival. Four weeks later I was scrambling around trying to figure out how to spend the last 48 GBP.

I have £30 in my wallet, I took it out about a month ago have not spend cash in six weeks. You can pay most of what you need by card.

The big reason now for cash is giving a tip, a £1 or £2, the places that are cash only, and coins and notes do make interesting souvenirs as they tell a story about the state or bank that issued them.

just a little.

I have a few pounds in my wallet, replenished in February I think. I had finally spent down the £70 which I took out in early 2020.

For me everything is paid with my phone, and very ocassionally an actual card. No cash. No cheques. Last cheque was about 15 or more years ago, last cash spend was ... I don't remember.

We returned from Scotland yesterday. One guest house was cash only, £130. For everything else we mostly used a card. One toilet only took cards so I have a charge on my Mastercard for 50p.