No, in terms of Clause (10) of Part I of First Schedule to the Chartered Accountants Act, 1949 it is not permitted to a Chartered Accountant or a firm of Chartered Accountant to charge fees on a percentage of turnover, except in the circumstances provided under Regulation 192 of the Chartered Accountants Regulations, 1988.

“192. Restriction on fees

No Chartered Accountant in practice shall charge or offer to charge, accept or offer to accept, in respect of any professional work, fees which are based on a percentage of profits, or which are contingent upon the findings, or results of such work: Provided that: (a) in the case of a receiver or a liquidator, the fees may be based on a percentage of the realization or disbursement of the assets; (b) in the case of an auditor or a co-operative society, the fees may be based on a percentage of the paid up capital or the working capital or the gross or net income or profits; and (c) in the case of a valuer for the purposes of direct taxes and duties, the fees may be based on a percentage of the value of the property valued. (d) in the case of certain management consultancy services as may be decided by the resolution of the Council from time to time, the fees may be based on percentage basis which may be contingent upon the findings, or result of such work; (e) in the case of certain fund raising services, the fees may be based on a percentage of the fund raised; (f) in the case of debt recovery services, the fees may be based on a percentage of the debt recovered; (g) in the case of services related to cost optimization, the fees may be based on a percentage of the benefit derived; and (h) any other services or audit as may be decided by the Council.