I have been talking with my brother-in-law about his "Part P" registration, having seen reports here I couldn't understand how he seemed to think he had "Part P approval". Well now I know, he's registered with ELECSA who are one of the part P registration organisations but seem much more oriented towards dealing with individuals.
He has a card which is personal to him which states he is a "Part P Approved Contractor", it does have his company name on it (he's a one man band) but the card is 'his' not his company's. To get his registration he has some C&G qualifications and has had some work inspected.