Bank sort code change - is it better to update existing sort code or create new one?

We have been allocated a new sort code for several of our bank accounts, to go live later this month.  I have looked at this on a test system and found two ways to do it:

1. Create a new bank branch with the new sort code and link the existing bank accounts to the new branch

2. Update the existing bank branch with the new bank sort code.

I'm looking for some advice on which way to do it.  Is there a best practice guidance note from Oracle?  Or have other users done this and have any recommendations?

Many thanks,

George Simpson