Time of supply of services: earliest of invoice issuance, payment receipt, provision of service, or recipient's book entry. The time of supply for services is the earliest of invoice issuance (if within prescribed period) or receipt of payment; if invoice is late, the earlier of provision of service or receipt of payment; otherwise the date the recipient records the service. For reverse charge, time of supply is earlier of recipient payment or the date following sixty days from supplier's invoice, with fallback to recipient's books; vouchers are timed by issue or redemption; unspecified cases follow return filing or tax payment dates; additions for interest or penalties are timed on receipt.