Converting a UK PPL(A) to a UK PPL(H)

To convert your PPL(A) to a PPL(H) you need to meet the following requirements:

• Be at least 17 years of age
• Hold a valid PPL(A) which is not suspended, cancelled or restricted
• Hold a current Class 2 or 1 Medical Certificate
• Hold a Flight Operator Radiotelephony Licence (FRTOL).
• Must pass the following PPL(H) theory examinations:
• Principles of flight
• Operational Procedures
• Flight performance and planning
• Aircraft General knowledge
• Must pass a PPL(H) Skills Test
• Must meet the minimum flight training experience requirements as listed in UK CAA Regulations FCL.210H

Applicants holding a pilot’s licence for another category of aircraft, with the exception of balloons, will be credited with 10% of their total time as PIC on such aircraft up to a maximum of 6 hours. The applicant must have a total minimum of 39 hours helicopter training, including 10 hours supervised solo flight. The amount to be credited, in any case, cannot include the P1 requirement below:

10 hours supervised solo flight time, including at least 5 hours cross country flight time with at least 1 cross country flight of at least 100nm with full stop landings at 2 aerodromes different from the aerodrome of departure.

https://www.caa.co.uk/general-aviation/pilot-licences/helicopters/private-pilot-licence-for-helicopters/