If you read your Bank or Building Society Terms and Conditions you will see terms like this : "In exceptional circumstances, it may be necessary to suspend your right to make withdrawals from an account.  In such cases, it may not be possible to give prior notice".  This is just one example which comes from the terms of an Abbey National account.  Here is another example from another UK high street bank - NatWest - "Unless you have made specific arrangements with us relating to the withdrawal of a sum in cash, we may limit the amount you may withdraw in cash at any time".  They all have much the same sort of qualifier - it goes with banking.