Exemption for RWA services limited to member contributions for third party goods or services; excess contributions attract service tax liability. Under the negative list regime, services by RWAs to their own members are exempt when contributions are reimbursements or shares for sourcing third party goods or services for common use, subject to a prescribed per member monetary ceiling; any member contribution exceeding that ceiling is wholly ineligible for the exemption and taxable. RWAs may claim threshold exemption subject to aggregate value rules that exclude exempt services; pure agent treatment can exclude certain pass through payments from taxable value; CENVAT credit is available under the Cenvat Credit Rules.