GST registration, filing and InvoiceNow — Timeline and processing benchmarks

Raffles Corporate Services works with a panel of corporate and employment law firms; this article is general information, not legal advice.

GST registration, filing and InvoiceNow are the three pillars of Singapore’s goods and services tax compliance. Businesses with taxable turnover exceeding S$1 million must register for GST, file periodic returns via myTax Portal, and — under the phased InvoiceNow initiative — adopt e-invoicing through the nationwide network for GST reporting.

What GST registration, filing and InvoiceNow cover

Goods and Services Tax (GST) is Singapore’s value-added tax on the supply of goods and services and on imports. Registration brings a business into the GST system; filing is the periodic reporting and payment of net GST; and InvoiceNow is the national e-invoicing network (based on the international Peppol standard) that IRAS is progressively integrating into GST reporting.

The prevailing GST rate in Singapore is 9%. Registered businesses charge GST on taxable supplies (output tax) and claim GST on business purchases (input tax), remitting the difference.

For related guidance, see GST Overseas Vendor Registration (OVR) Singapore (2026): Digital Services, Non-Digital Services and Low-Value Goods Rules.

Who must register for GST

Registration is compulsory where taxable turnover exceeds S$1 million in a 12-month period on a retrospective basis, or is reasonably expected to exceed S$1 million prospectively. Businesses below the threshold may register voluntarily to recover input tax. The registration obligation is set out in the Goods and Services Tax Act 1993.

The Act’s registration rules require a person whose taxable turnover crosses the threshold to notify the Comptroller and be registered, with penalties for late registration.

Filing GST returns and adopting InvoiceNow

GST-registered businesses file returns (Form GST F5) usually on a quarterly basis, reporting output and input tax and paying any net GST due. Returns and payment are due one month after the end of each accounting period. InvoiceNow adoption allows invoice data to flow directly through the network, and IRAS is phasing in a requirement for GST-registered businesses to transmit invoice data via InvoiceNow, starting with newly incorporated voluntary registrants.

Adopting InvoiceNow early reduces manual data entry and aligns the business with the direction of Singapore’s digital tax administration.

See also our cross-site guide: EP and S Pass Salary Floors Rising in January 2027: Employer Audit and Renewal Planning Guide.

GST registration, filing and InvoiceNow timeline and processing benchmarks

A complete GST registration application is generally processed by IRAS within a few weeks. Once registered, quarterly returns fall due one month after each quarter-end. Businesses adopting InvoiceNow should allow lead time to onboard an approved solution provider and connect to the network before their transmission obligation begins.

Compulsory registrants must apply within 30 days of becoming liable, so monitoring rolling 12-month turnover is essential to avoid late-registration penalties.

Rates, thresholds and numerical benchmarks

Key figures: GST rate 9%; compulsory registration threshold S$1 million taxable turnover; return and payment due one month after each accounting period; compulsory registration application within 30 days of liability. Voluntary registrants must generally remain registered for at least two years and comply with GIRO and e-filing conditions.

Common mistakes and gotchas

Businesses frequently register late by tracking only calendar-year turnover rather than a rolling 12-month window, mis-claim input tax on blocked expenses such as private car costs and entertainment, and file late. On InvoiceNow, a common error is leaving solution-provider onboarding to the last minute. Deregistration when turnover falls is also often overlooked.

Related guides and official resources

Further reading: GST registration, filing and InvoiceNow — Costs and fees breakdown; GST Overseas Vendor Registration (OVR) Singapore (2026): Digital Services, Non-Digital Services and Low-Value Goods Rules; EP and S Pass Salary Floors Rising in January 2027: Employer Audit and Renewal Planning Guide.

Official sources: www.iras.gov.sg | www.asc.gov.sg | www.acra.gov.sg.

FAQs

What is the GST registration threshold?
Taxable turnover exceeding S$1 million over a 12-month period, on either a retrospective or prospective basis.

What is the current GST rate?
The prevailing GST rate in Singapore is 9%.

How often are GST returns filed?
Most registered businesses file quarterly, with the return and payment due one month after the end of each accounting period.

What is InvoiceNow?
Singapore’s national e-invoicing network based on the Peppol standard, which IRAS is progressively integrating into GST reporting.

Need help with this? Call, SMS or WhatsApp +65 8501 7133, or email [email protected]. Raffles Corporate Services works with a panel of corporate and employment law firms; this article is general information, not legal advice.