If he's going via the NPPL route and has completed a SSEA GST then yes, because he needs to be a
NPPL holder in order to take advantage of the conversion agreement.
CAP 804, Section 4, Part P, page 11.
However, you could have completed a SEP proficiency check; he can then apply directly for a LAPL on the basis of his UK PPL with valid SEP class rating and LAPL medical. This would save him about £153 admin costs.
CAP 804, Section 4, Part P, page 23. 
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