There’s varying numbers of reasons why banks limit cash withdrawals.
- They don’t hold enough cash in their systems for everyone to take out their money
- They have to pay a fee (interchange fee?) to others banks or Link for usage
- Prevent fraud and money laundering
- Not enough currency exists for all the money in the banking system.
If you BACs £9999 or CHAPS anything higher it’s just a computer transaction. No money actually moves and that’s why it’s easier to do.