Paul O'Brien (asker) Nov 30, 2010:

yeah, i had a message from a bank guy today and he told me that when the three figures are missing it means the head office, and that they themselves usually add the missing three to denote their branch.

Thomas Roberts Nov 30, 2010:

sede I have a feeling that the last three letters are always xxx, except where the swift code is specific to the individual branch. For example my code is BPPIITRR (same code for all branches), but I often have to specify BPPIITRRXXX becuase some bank systems need to fill up all the letters.

Paul O'Brien (asker) Nov 30, 2010:

actually, the code for the "sede" is three figures shorter than the other one.