The invoice referred to in rule 46, in the case of the taxable supply of services, shall be issued within a period of thirty days from the date of the supply of service:

Provided that where the supplier of services is an insurer or a banking company or a financial institution, including a non-banking financial company, the period within which the invoice or any document in lieu thereof is to be issued shall be forty five days from the date of the supply of service:

Provided further that an insurer or a banking company or a financial institution, including a non-banking financial company, or a telecom operator, or any other class of supplier of services as may be notified by the Government on the recommendations of the Council, making taxable supplies of services between distinct persons as specified in section 25, may issue the invoice before or at the time such supplier records the same in his books of account or before the expiry of the quarter during which the supply was made.