I worked for a major UK bank for 28 years. The Banking Code requires all banks to make switching as smooth and pain-free as possible and all the main banks have teams dedicated to making sure it happens. They have to liaise over the transfer of standing orders and direct debits (the cause of most hassle), and balances, whether credit or debit, must be transferred automatically. In the case of a debit balance, obviously the new bank must have agreed to an overdraft facility. Under the code, the new bank is also obligated to explain the switching process to you, so they've failed in their first duty to you as a customer!
Here are the relevant sub-sections of the code:
7.1 If you decide to move your current account to another bank, we will give them information on your standing orders and direct debits within three working days of receiving their request to do this. Also, we will close your account without unnecessary delay when you ask us to do so.
7.2 We will not make any extra charges for either closing or switching a current account except those already agreed with you or agreed at the time you ask us to close or switch your account.
7.3 If you ask us, we will tell you our policy on whether or not we will pay any legal or valuation charges for the transfer of any security to us.
7.4 If you ask us to, we will give your new bank details of your credit history with us.
7.5 If you want to transfer your current account to us,
we will tell you how the process for transferring your account to us will work and where responsibility will lie for each step in the process, including:
- what information your old bank will pass to us;
- what features you will be offered with the new account so that you can compare your new account with features on your old account; and
- how long the transfer is likely to take.
We will give you what you need to operate the account within 10 working days of approving your application.
7.6 We will cancel any bank charges you have to pay as a result of any mistake or unnecessary delay by us when you transfer your current account to or from us.