Invoice vs Bill vs Receipt vs Voucher: The Legal Differences

In everyday conversation, "invoice," "bill," and "receipt" are near-synonyms. Under GST, they're specific document types with different legal purposes, and using the wrong one isn't just informal — it can mean you haven't actually issued the document the law required for that transaction.

Tax invoice

Issued by a registered supplier when GST is charged. This is the document that carries a customer's input tax credit — see the full checklist for what it legally must contain.

Bill of supply

Issued instead of a tax invoice when no GST is charged — exempt supplies, or by a composition dealer. See bill of supply vs tax invoice for exactly when each applies.

Receipt / payment voucher

A receipt acknowledges that a payment was received — it's not a tax document in itself. Under GST, an advance payment received before an invoice exists needs its own receipt voucher, a specific document type distinct from the eventual tax invoice for the full sale.

Refund voucher

Issued when an advance payment is refunded before the underlying supply was ever made — the counterpart to a receipt voucher, closing out an advance that never became an invoice.

Credit note and debit note

Neither is a fresh invoice — both are corrections to a value already invoiced. They're separate document types with their own numbering, not informal adjustments layered onto the original invoice.

Why the distinction is worth getting right

Calling something "a bill" or "a receipt" colloquially is harmless. Issuing the wrong legal document type for a transaction — a tax invoice where a bill of supply was required, or nothing at all where a receipt voucher was needed for an advance — is a real gap, and it's usually invisible until someone reconciles the paper trail against what actually happened.