HSBC were brilliant with me when I wanted to switch my current account. I had been with Natwest years and was fed up of the appalling customer service. I knew I may have problems as there is a notice of correction on my credit report which is otherwise fair/good, this means I cannot be electronically scored and the decision is down to an underwriter.
The process took a little longer than usual but I was accepted no problems and the customer service so far has been second to none. They kept me updated at every stage and the lady even worked late one evening to get my documents in the post for me. I am a happy customer.