From LASORS2007:
D1.2(A) NOTES
An applicant may be admitted to training as an ab-initio
entrant, or as a holder of a PPL(A) or PPL(H) (excluding
NPPL) issued in accordance with ICAO Annex 1. In the
case of a PPL(A) or PPL(H) entrant, 50% of the aircraft
hours flown by the entrant prior to the course may be
credited towards the required flight instruction up to a
credit of 40 hours flying experience or 45 hours if an
aeroplane night flying qualification has been obtained,
of which up to 20 hours may be dual instruction. This
credit for the hours shall be at the discretion of the FTO
and entered into the applicant’s training record, and is
subject to confirmation by the FTO at the time of
application. In the case of a student pilot who does not
hold a pilot licence and with the approval of the
Authority, a FTO may designate certain dual exercises
(see AMC FCL 1.160 & 1.165(a)(3), phase 2 & 3) to be
flown in a helicopter of a TMG up to a maximum of 20
hours.