I have been with the company for a while but when I first started, there was a 3 stage process. 1st was to fill in the application and once you have successfully passed this, you would have to do an English and maths test via computer within 24 hours. Once you have passed this, a telephone interview was set up and you had to say why you interviewed for the position, what do you know about TSB and what products/ services they sell. This took about 30 mins. Once you have passed this a F2F interview would determine whether you get it. You would be interviewed by a branch manager, not necessarily the one you would be working with. They ask you plenty of questions such as, why do you want the job, are you willing to travel, competency questions (what would you do in certain scenarios etc). This took on average an hour. Once this is done, they call on the same day.
However, I understand the process is slightly different now. You would still have the 3 stage process but instead of the telephone interview, there is a virtual video interview instead. You will be recorded and get 3 mins on each question. Once you have passed this, you will then move on to the F2F.