Refund eligibility for inward supplies requires invoice and GSTIN presence; claims filed electronically with prescribed forms. Persons eligible under section 55 may apply once every quarter in FORM GST RFD-10 electronically or via a notified Facilitation Centre with FORM GSTR-11; acknowledgement is FORM GST RFD-02. Refunds require receipt from a registered person against a tax invoice exceeding five thousand rupees (excluding tax), inclusion of applicant name and GSTIN or UIN on the invoice, and satisfaction of other notification conditions; rule 4 applies mutatis mutandis to sanction and payment, and inconsistent treaties prevail.