Thanks for the replies guys. sorry to be slow getting back to you, and yes Vikpaw, you have hit the nail on the head (and thanks for getting to the essence of my rather vague question!). The problem has now become more eiviident as the Headteacher is now frusrated that the school's convention for staff ID composition have not been followed and now wants to change them all, which has a knock on-effect on ParentPay. ParentPay are quite happy to edit their end but I am now wondering what else (Show my Homework, Evolve, Sam Leaning, Groupcall etc) which are administered by various staff.
Actually, I am taking this as an opportunity to resolve a bunch of issues and get more hygienic routines in place for the school and am working with the (new and untrained) SIMS manager on some algorithms to deal with ID management. Want to cover end to end, creation to retirement of IDs and deal with any Data Protection compliance at the same time.