A Bill of Supply should have the following details:
(a) Name, address, GSTIN of the supplier
(b) Consecutive Serial Number unique for a financial year having alphabets/ numerals and special characters being “-“ or “ / “ only
(c) Date of Issue
(d) Name, address of the recipient and GSTIN/UID of the recipient, if registered
(e) HSN code of Goods or Services
(f) Description of Goods / Services
(g) Post discount/abatement value of Goods and Services
(h) Signature/Digital Signature of the Suppler or his authorized representative.
Further, provisos to rule 46 shall, mutatis mutandis, apply to the bill of supply.
Furthermore, any tax invoice or any other similar document issued under any other Act for the time being in force in respect of any non-taxable supply shall be treated as a bill of supply for the purposes of the Act.
(ICAI FAQ PUBLICATIONS 06-09-2017 TAX INVOICE, CREDIT AND DEBIT NOTES: FAQ NO. 32)