GST interest on delayed refunds: template requires refund amount, delay period, rate, and interest split by tax heads. Standardized Form GST RFD-09 prescribes an order format for computing interest on delayed refunds, requiring identification of the taxpayer and refund sanction reference, and specifying refund amount, rate of interest, period of delay (days/months) and calculated interest amounts separately for CGST/IGST and SGST, with fields for date, place, DSC signature, name, designation and office address to authenticate the sanction.