Refund of excess electronic cash ledger: no time limit; unjust enrichment not required; deemed export refund tied to supplier return. Refunds of excess balance in electronic cash ledger are not subject to the time limit in section 54(1) and do not require unjust enrichment certification. TDS/TCS credited to the electronic cash ledger is equivalent to cash and may be used or refunded as excess balance after discharge of dues. For supplies regarded as deemed exports, the relevant date for refund claims is the date the supplier furnishes the return relating to those supplies.