OU Credit Transfer?

I have a friend looking into this, and though TSR would be a good place to ask.

He has completed a year (120 credits) of an IT degree with the open university. He is considering potentially switching to the Combined STEM and taking some psychology modules.

If he were to complete this he knows it won't be accredited by BPS, but could he (after graduating with combined stem degree) do addition psychology module credits in order to get the psychology degree (using credit transfer from psychology modules on previous degree)?

E.g. If 240 credits are IT modules, 120 are psychology modules, could he take a further 240 credits of psychology modules and use credit transfer to get BSc Psychology?