Re: Determining PRSI scales?
I can see why you are confused. Just glanced at the site that you gave a link to and it appears that Scale A or B is for local authorities and health. The Civil Service rates are the maximum that you can pay, if you wish to pay over you need to get authority from the Revenue Commissioners.
Scale A or B are not references to PRSI. Payments made under these are not subject to tax or prsi, they are net payments made for useage of private cars for work related matters, covering fuel, costs, and wear and tear. Hope this helps.