Just use Starling bank, you can deposit cash via postoffice.
See hereWhats the monthly cash limit on Starling and do you need to be a business?
See here
Starling Customer Service (IMO, limits are not so bad and you need not to be a business.)
Yes. Frankly, it is understandable for me; I presume (and I guess you tooOk so you need to ask them what your personal limit is as they don't tell you.
"For Personal and Joint Current Accounts, there are individual limits on the amount of cash that can be deposited in each account. If you need to find out more about your specific annual limit, please contact us by chatting with us in the app."