GST and InvoiceNow for Singapore Online Sellers: A Checklist

Many sellers assume InvoiceNow is something to install on the store. IRAS describes it differently: GST-registered businesses submit invoice data through InvoiceNow-Ready Solutions, such as accounting software, or an in-house system connected to an accredited Access Point Provider.

Your website still matters: it shows prices and starts orders. This guide separates what the website must do from what the accounting side must do, and ends with a checklist. Facts were checked against IRAS and IMDA pages on 29 October 2026. It is educational, not tax or legal advice.

Quick answer

Does InvoiceNow apply to you yet?

The GST InvoiceNow Requirement is mandatory for GST-registered businesses and is being rolled out in phases. Two phases are already in effect, and the remaining dates depend on your registration and your size.

For existing businesses, "total annual supplies" means Box 4 of your GST returns for the prescribed accounting periods ending in calendar year 2025. IRAS has notified businesses registered before 2026 of their dates. If you received no notice, for example because you had no GST returns for periods ending in 2025, IRAS says your date will be communicated later.

Overseas entities, including overseas vendors under the Overseas Vendor Registration regime, and businesses liable to register only because of the reverse charge, are excluded.

Check whether GST registration applies to you

IRAS applies two tests. On the calendar-year basis, you must register if taxable turnover for the year is more than S$1 million, applying between 1 and 30 January of the following year. On the forecast basis, you must register if you can reasonably expect it to exceed S$1 million in the next 12 months, applying within 30 days after the forecast date. Keep documents that support a forecast, such as signed contracts or confirmed purchase orders; sales targets alone are not enough.

The application deadline is not the effective registration date, which IRAS sets separately. Exceptions and exemptions exist, so check the IRAS registration page. Below these tests, registration is voluntary.

That choice has an InvoiceNow consequence. A business that applies for voluntary registration on or after 1 April 2026 falls into the 1 April 2026 phase. Factor the cost of compliant accounting software into the decision, not only the GST you could claim back.

What your website must show: GST-inclusive prices

If you are GST-registered, you must display and quote prices inclusive of GST. IRAS applies this to price tags, advertisements and website prices, and says non-compliance can lead to a fine of up to S$5,000. The current GST rate is 9%.

Two more rules matter for online shops. Phrases such as "prices are exclusive of GST" are not allowed without the GST-inclusive price. And if you discount an item by the amount of GST, you cannot advertise "no GST", because GST is still included in the price after the discount.

Order emails, receipts and tax invoices

A checkout confirmation is not automatically a tax invoice. IRAS requires all the necessary information on a single document, and missing details can stop your customer from claiming input tax. Which document you issue depends on who is buying.

A full tax invoice must show:

• the words "Tax Invoice" in a prominent place;
• your name, address and GST registration number;
• the issue date and a unique invoice number;
• the customer's name and address;
• a description of the goods or services and the GST rate;
• the total excluding GST, the GST amount and the total including GST, in Singapore dollars.

If an invoice is in a foreign currency, convert those amounts using the exchange rates approved for GST purposes. If invoices go out by email from your own domain, SPF, DKIM and DMARC setup helps them reach inboxes rather than spam folders.

Export orders and services sold online

IRAS says the same GST rules apply whether you sell online or offline. Goods sold online and delivered in Singapore are standard-rated. You may zero-rate goods you export if you keep the required export documents. Services supplied over the internet to local customers are standard-rated, and zero-rating applies only if they qualify as international services.

If you lose export evidence, IRAS says you must treat the sale as a local supply and account for 9% GST. Keep that evidence with the order record.

Connect the store to your accounting software

InvoiceNow does not ask your website to send anything to IRAS. IRAS receives a copy of your invoice data through IMDA-accredited Access Point Providers once you activate the submission feature. The practical work is making sure your store's orders reach your accounting system.

1. Check whether your accounting software is on IMDA's list of accredited InvoiceNow-Ready Solutions, or whether a free-of-charge package suits you.
2. Ask your solution provider to register your business in the SG Peppol Directory with your UEN, which gives you a Peppol ID.
3. Activate the GST InvoiceNow submission feature.

IRAS says onboarding can take as little as 3 months, and most businesses finish within a year. Businesses with their own in-house system should contact an accredited Access Point Provider.

The data covers transactions in your GST return: standard-rated supplies and purchases, zero-rated supplies and purchases, and exempt supplies. That includes sales invoices, tax invoices, simplified tax invoices, serially numbered receipts, debit notes and credit notes. IRAS allows businesses to aggregate supplies data from point-of-sale systems. Submit by the earlier of the date you file the relevant GST return or its filing due date.

Grants and free options

IRAS lists a GST InvoiceNow Transition Grant of S$1,000 for SMEs with annual supplies up to S$4,000,000. Free-of-charge solution packages are available up to 31 March 2031, although the current package list only runs to 31 March 2027. Check IMDA's InvoiceNow grants page for eligibility before you buy.

Your pre-flight checklist

• Confirm whether you are GST-registered and which InvoiceNow date applies to you.
• Search product pages, the cart, ads and quote templates for any "+ GST" wording.
• Confirm each order produces the right document for GST-registered and other buyers.
• Check the invoice template for the "Tax Invoice" label, your GST registration number and an invoice number.
• Map how orders, payments and refunds reach your accounting system, including credit notes for returns.
• Confirm that supplier invoices and expense records for standard-rated and zero-rated purchases also reach your accounting system, not only store sales.
• Confirm your software is accredited, and that your Peppol ID is registered against your UEN.
• Keep GST records for at least 5 years, including data from any software you retire.
• Name one person to review these items before each GST return.

Common mistakes to avoid

Where your website and hosting fit in

Hosting does not make a store GST-compliant, but it serves the checkout pages that show your prices and holds order data your records depend on. When comparing plans, ask about backups, SSL and checkout traffic. Z.com's web hosting page lists a free SSL certificate. Confirm backup method, frequency and restore conditions, plus current SGD pricing and GST treatment, on the plan page before you order.

If checkout slows down during campaigns, read when to upgrade from shared hosting. For protection around payments and logins, use our small business website security checklist.

Frequently asked questions

Sources

• IRAS: GST InvoiceNow Requirement
• IRAS: Displaying and quoting prices
• IRAS: Invoicing customers
• IRAS: Keeping records
• IRAS: Do I need to register for GST
• IRAS: GST for e-commerce
• IRAS: Current GST rates
• IMDA: Nationwide e-Invoicing Framework

This article is general educational information, not tax or legal advice. GST rules and InvoiceNow dates can change, so confirm your position with IRAS or a qualified adviser.