What is Bill of Supply?
A bill of supply is a GST billing document used when the supplier is not allowed to collect tax on the invoice. The two common cases are businesses supplying only exempt goods or services, and taxpayers under the composition scheme, who pay tax on turnover at a fixed rate but cannot charge GST to customers. It looks much like an invoice, with supplier details, a serial number, date, recipient and value, but it carries no tax amount.
Why it matters for exporters
Export of services is not an exempt supply. It is a zero-rated supply under Section 16 of the IGST Act, and that difference matters. A zero-rated export is taxable in principle but taxed at zero, either under LUT (no IGST charged) or with IGST paid and then refunded. A registered exporter therefore normally issues a tax invoice for exports, not a bill of supply, and an LUT invoice must carry the wording "Supply meant for export under LUT without payment of IGST".
Using a bill of supply for an export by mistake can cause trouble with refunds of input tax credit and with how the supply is reported in GSTR-1. The EDF itself only needs your invoice number, date, currency and amount, but the document behind it should be the right one.
Example
Meera runs a small tuition centre in Indore that provides only exempt educational services locally, so she issues bills of supply to parents. Separately, her cousin's firm, Rudra Web Services, builds websites for clients in Canada. Rudra is GST-registered, exports under LUT and issues tax invoices with zero IGST and the LUT wording, using the export invoice tool. Those invoices go on Rudra's monthly EDF.
Common confusion
Zero-rated and exempt are often mixed up. Exempt means no tax and generally no input credit; zero-rated means tax at zero with credit available. Our article on tax invoice vs bill of supply walks through which one to issue. Confirm your specific case with a CA.