.. head office using all its human resources to facilitate the operational requirements of the branch offices/units by way of procuring common input services on behalf of the branch offices/units thereby, providing the services, therefore, allocation and recovery of any amount including its employees salary cost from the branch offices/units will be subject to GST. Hence, the allocation and recovery of the salary of the employees of the head office from the branch office/units will be subject to GST.
Source: a2ztaxcorp.com