Just get a bank account for your rentals. Simple.

I was using QuickBooks but hated the fact I was paying an increasingly large amount and they were offering a 90% discount to new customers.
I got a Monzo account and it does everything I could want it to do. I have pots for tax savings, pots for maintenance. I scan and label all my receipts. I have a large white board with all the properties info on, gas certs, epc’s, insurance etc.