Singapore GST Invoice Requirements (2026): Tax Invoice Rules

In Singapore, the invoice you send depends on whether your business is registered for Goods and Services Tax (GST). GST-registered businesses must issue a proper tax invoice that follows the format set by the Inland Revenue Authority of Singapore (IRAS), because that document is what lets your customer claim back the GST they paid. Get a field wrong or leave one out and IRAS can treat the invoice as non-compliant. This guide walks through what a Singapore tax invoice must contain, the current GST rate, and the simpler options for small sales and non-registered businesses.

The current GST rate

Singapore's GST rate is 9%, which took effect on 1 January 2024 after a two-step increase from 7%. It is a broad-based tax on most goods and services supplied in Singapore and on imports. If you are GST-registered, you charge 9% on your standard-rated supplies and show it clearly on the invoice. Always confirm the prevailing rate on the IRAS website before issuing, since rates can change with the annual Budget.

Who has to issue a tax invoice

Only GST-registered businesses issue tax invoices. Registration is compulsory once your taxable turnover exceeds the registration threshold, and some businesses register voluntarily. If you are not GST-registered, you must not charge GST or issue a document labelled 'tax invoice' - you simply send an ordinary invoice with no GST line. Charging GST when you are not registered is an offence, so only add a GST amount once your registration is confirmed.

What a Singapore tax invoice must show

IRAS sets out the details a standard tax invoice must contain. Make sure yours includes all of the following:

• The words 'Tax Invoice' shown prominently.
• Your business name, address and GST registration number.
• An identifying serial number (your invoice number).
• The date the invoice is issued.
• Your customer's name and address.
• A description that identifies the goods or services supplied.
• For each item, the quantity or volume, and the amount payable excluding GST.
• The total amount payable excluding GST, the GST rate, and the total GST charged shown as a separate amount.
• The total amount payable including GST.

The two things businesses most often get wrong are leaving off the GST registration number and rolling the GST into the total instead of showing it as its own line. Keep the tax clearly separated so your customer can see exactly how much GST they were charged.

When a simplified tax invoice is allowed

If the total amount payable including GST is SGD 1,000 or less, IRAS lets you issue a simplified tax invoice. This is common in retail and food and beverage, where printing full customer details on every receipt is impractical. A simplified tax invoice still needs your business name, address and GST registration number, the date, an identifying number, a description of the goods or services, and the total payable with a statement that it includes GST. Your customer's name and address are not required on the simplified version.

E-invoicing and InvoiceNow

Singapore is phasing in InvoiceNow, a national e-invoicing network based on the Peppol standard, with GST-registered businesses being brought on in stages. InvoiceNow does not change the information a tax invoice must carry - the same mandatory fields apply. What changes is delivery: instead of emailing a PDF, the invoice is transmitted as a structured data file between accounting systems. If you are a small business emailing PDF invoices today, check the current IRAS timeline to see when it may apply to you.

Records and rounding

Keep copies of the tax invoices you issue and receive for at least five years, as IRAS can ask to see them. When you have several lines, it is cleaner to total the GST once at invoice level rather than rounding on every line. Whatever method you use, be consistent so your GST return reconciles against your invoices.

New to invoicing? Start with what to include on an invoice. Comparing Singapore's rules with its neighbours? See our guides on New Zealand GST invoice requirements and UAE VAT invoice requirements.