According to Rule 94 of Central Goods and Service Tax Act, 2017 as passed by Lok Sabha :
Where any interest is due and payable to the applicant under section 56, the proper officer shall make an order along with a payment advice in FORM GST RFD-05 , specifying therein the amount of refund which is delayed, the period of delay for which interest is payable and the amount of interest payable, and such amount of interest shall be electronically credited to any of the bank accounts of the applicant mentioned in his registration particulars and as specified in the application for refund.