There is no such thing as a Part P Qualified electrician, in the same way that there is no such thing as a Part P exam. Part P is a section of the building regs appertaining to electrical installations in domestic dwellings.
To say that you are Part P registered merely confirms that you satisfy the minimum scheme entry requirements of one (or other) of the Part P registration bodies (i.e. you can read and write and understand the basic requirements of both BS7671 and Part P of the building regs.).
If it was possible to legitimately comply with Part P wihtout incurring any costs we would all be doing it wouldn`t we!