For many business owners in Singapore, Goods and Services Tax (GST) registration is a milestone that raises a host of questions. When is registration compulsory? Is there any benefit to registering voluntarily? What are the compliance obligations that come with being GST-registered? And with the new InvoiceNow requirements rolling out from April 2026, what should businesses expect?

This guide provides a comprehensive overview of GST registration in Singapore, covering the thresholds, the process, and the ongoing obligations that GST-registered businesses must fulfil. Whether you are approaching the $1 million turnover mark or considering voluntary registration, understanding the rules will help you plan ahead and avoid costly penalties.

What Is GST and Who Needs to Register?

GST is a broad-based consumption tax levied on the supply of goods and services in Singapore, as well as on the importation of goods. The current GST rate is 9%, which took effect from 1 January 2024. GST is administered by the Inland Revenue Authority of Singapore (IRAS).

Not every business needs to be GST-registered. Registration is required only when certain turnover thresholds are met — or a business may choose to register voluntarily even if those thresholds have not been reached. Understanding whether your business needs to register is an important part of your overall compliance requirements.

Compulsory GST Registration

Under the Goods and Services Tax Act, a business must register for GST if its taxable turnover exceeds S$1 million. There are two bases on which this threshold is assessed.

The first is the retrospective basis: if your taxable turnover for the past 12 months has exceeded S$1 million, you are required to register. You must apply to IRAS for GST registration within 30 days of the date your turnover exceeds the threshold. Your effective date of registration will be within 30 days of your application, unless otherwise determined by the Comptroller.

The second is the prospective basis: if you have reasonable grounds to believe that your taxable turnover in the next 12 months will exceed S$1 million, you must also register. This could arise, for example, if you have just secured a large contract or are expanding into a new market.

It is important to monitor your turnover regularly. Failure to register on time can result in backdated registration, and you will be required to account for and pay GST on past sales from the effective date of registration — even if you did not collect GST from your customers during that period. This can be a significant financial burden. If you need help tracking your company’s financial position, consider engaging professional corporate tax filing and bookkeeping services.

Voluntary GST Registration

Businesses that do not meet the S$1 million turnover threshold may still apply to register for GST on a voluntary basis. There are genuine commercial reasons why a business might choose to do so.

One key advantage is the ability to claim input tax credits. Once GST-registered, a business can claim back the GST it pays on its purchases and expenses (known as input tax). This can be particularly beneficial for businesses that incur significant costs on goods and services — for example, a company that imports raw materials or invests heavily in equipment.

However, voluntary registration also comes with obligations. Businesses that register voluntarily are generally required to remain registered for at least two years. They must also comply with all GST filing and record-keeping requirements, which can add to the administrative workload. Before deciding to register voluntarily, it is advisable to weigh the potential input tax savings against the compliance costs. Our guide to corporate tax in Singapore provides further context on the broader tax landscape.

The GST Registration Process

GST registration is done online through IRAS’s myTax Portal. The key steps are as follows.

First, determine whether you need to register on a compulsory or voluntary basis. Gather the necessary information about your business, including your UEN (Unique Entity Number), your financial year end, your taxable turnover figures, and details of the goods or services you supply.

Next, log in to the myTax Portal using your CorpPass credentials and submit the GST registration application. IRAS will review your application and may request additional documents or information.

Once approved, IRAS will issue a GST registration number and confirm your effective date of registration. From that date, you must charge GST on your taxable supplies, issue tax invoices, file GST returns (typically on a quarterly basis), and maintain proper records for at least five years.

Your company secretary or tax adviser should be involved in this process to ensure all filings and registrations are handled correctly.

New InvoiceNow Requirement from April 2026

One of the most significant recent developments in GST compliance is the introduction of the GST InvoiceNow Requirement. InvoiceNow is Singapore’s nationwide e-invoicing network, based on the international Peppol standard, developed by the Infocomm Media Development Authority (IMDA).

Under this requirement, GST-registered businesses will be required to transmit invoice data to IRAS digitally using InvoiceNow-ready solutions. The requirement is being rolled out in phases.

From 1 November 2025, all newly incorporated companies that voluntarily register for GST are required to comply with the InvoiceNow requirement as a condition of their GST registration. From 1 April 2026, this extends to all new voluntary GST registrants, regardless of their incorporation date. The requirement will then be progressively expanded to cover all GST-registered businesses by April 2031.

The phased rollout for existing businesses is as follows: from April 2028, new compulsory registrants and existing GST-registered businesses with annual taxable turnover not exceeding S$200,000; from April 2029, those with turnover up to S$1 million; from April 2030, those with turnover up to S$4 million; and from April 2031, all remaining GST-registered businesses.

The Government is providing financial assistance to help businesses adopt InvoiceNow solutions, including funding support of up to S$1,000 for SMEs and up to S$5,000 for larger corporations. SMEs can access InvoiceNow-ready solutions at no cost until March 2031.

This is an important development that all GST-registered businesses — and those considering voluntary registration — should be aware of. Businesses that are planning to register for GST voluntarily from April 2026 onwards should factor in the InvoiceNow requirement as part of their compliance preparations.

Ongoing GST Compliance Obligations

Once registered, GST-registered businesses must comply with several ongoing obligations. These include charging GST at the prevailing rate (currently 9%) on all taxable supplies, issuing tax invoices for all standard-rated supplies exceeding S$200, filing GST returns (Form 5) by the due date (one month after the end of each accounting period, typically quarterly), paying any net GST due to IRAS by the filing deadline, and maintaining proper records and accounts for at least five years.

Failure to comply with these obligations can result in penalties, including fines and even prosecution in serious cases. It is essential to have robust accounting systems in place to track GST collected and input tax claimed. Companies should also ensure their Estimated Chargeable Income (ECI) filings and corporate tax returns are aligned with their GST reporting.

GST Exemptions and Zero-Rated Supplies

Not all supplies are subject to GST at 9%. Some supplies are exempt from GST, meaning no GST is charged and no input tax can be claimed on related expenses. These include the sale and rental of residential properties, and certain financial services.

Other supplies are zero-rated, meaning GST is charged at 0% but the business can still claim input tax on its expenses. The most common zero-rated supplies are the export of goods and the provision of international services.

Understanding the distinction between standard-rated, zero-rated, and exempt supplies is important for correctly filing GST returns and maximising input tax claims. Our guide on tax exemption schemes in Singapore provides further detail on available reliefs.

GST Deregistration

A business may apply to cancel its GST registration if its taxable turnover falls below S$1 million and it does not expect to exceed this threshold in the next 12 months. However, as mentioned, voluntarily registered businesses must generally remain registered for at least two years.

When deregistering, the business must account for GST on any remaining stock and assets on hand, as well as any outstanding supplies. IRAS will also require the business to file all outstanding GST returns before the deregistration is finalised. If your business is winding down, you may also wish to read our guide on closing down your Singapore company.

Common Mistakes to Avoid

There are several common pitfalls that businesses encounter with GST registration and compliance. Failing to register on time when turnover exceeds S$1 million is one of the most costly errors, as it can lead to backdated registration and significant penalties. Incorrectly claiming input tax on exempt supplies or private expenses is another frequent issue. Not issuing proper tax invoices, filing GST returns late, and failing to maintain adequate records for the required five-year period are also common compliance failures.

These mistakes can be avoided by engaging qualified professionals to manage your GST compliance. If your company is new to GST, a corporate secretary and tax adviser can help set up the necessary systems and processes from the outset.

Conclusion

GST registration is a significant step for any Singapore business, bringing both opportunities (input tax recovery) and obligations (filing returns, issuing tax invoices, maintaining records). With the new InvoiceNow e-invoicing requirements now taking effect for new voluntary registrants from April 2026, businesses should plan their GST registration and compliance strategy carefully.

Whether you need to register compulsorily or are considering voluntary registration, Raffles Corporate Services can assist you with the entire process — from assessing whether registration is beneficial for your business, to handling the application with IRAS and setting up your compliance systems. Contact us today for professional guidance on GST registration and all your corporate compliance needs.

— The Editorial Team, Raffles Corporate Services