Slight thread drift but an interesting point that cotterpot raised was that you actually need 13 hours: 12 as PIC plus an hour with an instructor. As that is different from the NPPL, those who have converted may easily be caught out. The NPPL revalidation requirements being:
(i) flown at least 12 hours which includes at least 8 hours as pilot in command;
(ii) completed at least 12 take-offs and 12 landings;
(iii) undertaken at least one hour of flying training with an instructor entitled to give instruction on aeroplanes of that class; and
(iv) flown at least six hours in the 12 months preceding the specified date