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Guide · Singapore · Published 2026-10-11

How to invoice in Singapore: what to include

The fields a Singapore invoice needs, how to number and date it, when to show GST, the e-invoicing rules, and how to fix a mistake with a credit note.

  • S$ SGD
  • GST 9%
  • UEN
  • A4
  • English

What every invoice must show

  • A tax invoice with the words Tax Invoice, the GST registration number and the GST amount at 9%; simplified invoices not exceeding S$1,000.

Numbering, keeping and correcting invoices

A GST tax invoice must carry the words "tax invoice" prominently, an identifying number, the date of issue, the supplier's name, address and GST registration number, the customer's name and address, a description of each supply with quantity and the amount excluding GST, any cash discount, the GST rate and total GST as a separate amount, and the total including GST. It must be issued within 30 days of the time of supply.

Issue one original per sale. A lost original is replaced by a copy marked "Copy" or "Duplicate". When the total including GST does not exceed S$1,000, a simplified tax invoice with fewer particulars and the words "Price Payable includes GST" is allowed. Where the total is above S$1,000 the customer's name and address may not be replaced by "Cash".

Business records must be kept for at least five years, on paper or electronically. Failing to do so is an offence under section 46(6) of the GST Act, punishable by a fine of up to S$5,000, up to six months in prison, or both, and up to S$10,000 or three years for a repeat conviction.

Electronic invoicing in Singapore

InvoiceNow (Peppol) phases in by size: new voluntary registrants from 1 November 2025 and 1 April 2026, then existing businesses by annual supplies, from 1 April 2028 for the smallest through 1 April 2031 for those above S$4 million. Confirm your wave with IRAS.

Sources

How this guide was made

Written from published tax-authority guidance and reviewed on 2026-10-11. Everything here is indicative rather than a ruling on your circumstances, and rules change. Confirm anything you rely on with Inland Revenue Authority of Singapore (IRAS) before acting on it, and tell us if you find something out of date so we can correct it.

This guide explains the rules in general terms and is not tax advice for your circumstances. Confirm your position with a qualified adviser or with Inland Revenue Authority of Singapore (IRAS).