GST Registration and Compliance Guide for Singapore Businesses

Understanding GST in Singapore

The Goods and Services Tax (GST) is a broad-based consumption tax levied on the import of goods and on nearly all supplies of goods and services in Singapore. The current GST rate is 9%, which took effect from 1 January 2024. GST is administered by the Inland Revenue Authority of Singapore (IRAS).

For business owners, understanding GST is essential — not only because it affects your pricing and cash flow, but also because non-compliance can result in penalties, fines, and even prosecution.

When Must You Register for GST?

GST registration in Singapore can be either compulsory or voluntary.

Compulsory Registration

You must register for GST if:

• Retrospective basis: Your taxable turnover for the calendar year (1 January to 31 December) exceeds S$1 million. You must apply for GST registration between 1 January and 30 January of the following year, and your effective registration date will be 1 March of that year.
• Prospective basis: At any point in time, you can reasonably expect your taxable turnover in the next 12 months to exceed S$1 million. You must apply for GST registration within 30 days of the date of your forecast.

Important note: If your taxable turnover exceeds S$1 million during the year but you do not reasonably expect it to exceed S$1 million in the next 12 months, you are not required to register immediately. You may wait until the calendar year ends and apply under the retrospective basis.

New from 1 July 2025: Businesses liable for GST registration on a prospective basis will be given a two-month grace period to start charging GST, as announced by the Second Minister of Finance on 28 February 2025. Previously, businesses were required to charge GST on the 31st day after the date of forecast.

Voluntary Registration

Even if your turnover is below the S$1 million threshold, you may choose to register voluntarily. This can be beneficial if your business incurs significant GST on purchases (input tax) that you would like to claim back. However, once voluntarily registered, you must remain registered for at least two years and comply with all GST obligations.

How to Register for GST

GST registration is done online through the IRAS myTax Portal. The process typically involves:

1. Prepare your documents — You will need your company's financial records, details of taxable supplies, and projected turnover figures.
2. Submit the application — Log in to myTax Portal using your CorpPass and complete the GST registration form.
3. Receive your GST registration number — IRAS will process your application and issue a GST registration number, which must appear on all tax invoices.

For retrospective registration, the effective date is 1 March of the year following the calendar year in which your turnover exceeded S$1 million. For prospective registration, the effective date is either the 31st day after your forecast date (before 1 July 2025) or two months from your forecast date (from 1 July 2025 onwards). From the effective date, you must charge GST on all taxable supplies.

Issuing Tax Invoices

As a GST-registered business, you are required to issue a tax invoice for all standard-rated supplies made to GST-registered customers. A valid tax invoice must include:

• Your business name, address, and GST registration number
• The customer's name and address
• Invoice date and a unique invoice number
• Description of goods or services supplied
• The total amount payable, the GST amount, and the GST-inclusive price
• The words "Tax Invoice" displayed prominently

For supplies below S$1,000, a simplified tax invoice may be issued, which requires fewer details.

Claiming Input Tax

One of the key benefits of GST registration is the ability to claim input tax — the GST you pay on business purchases and expenses. To claim input tax, you must:

• Hold a valid tax invoice from your supplier
• Use the goods or services for business purposes
• Ensure the claim is made within five years from the end of the prescribed accounting period

Not all input tax is claimable. Common items that are blocked from input tax claims include:

• Club subscription fees
• Medical and accident insurance premiums for employees (unless compulsory under the Work Injury Compensation Act)
• Benefits provided to the family members of employees
• Costs related to motor cars (with limited exceptions)

Filing GST Returns (GST F5)

GST-registered businesses must file quarterly GST returns, known as the GST F5 form, through the IRAS myTax Portal. Each return covers a three-month accounting period.

Key Information in the GST F5 Return

The return requires you to declare:

• Total value of standard-rated supplies — All goods and services you supplied at the standard GST rate
• Total value of zero-rated supplies — Exports and international services
• Total value of exempt supplies — Financial services, sale of residential properties, etc.
• Total output tax — GST collected from customers
• Total input tax — GST paid on business purchases
• Net GST payable or refundable — The difference between output tax and input tax

Filing Deadlines

GST F5 returns must be filed within one month after the end of each accounting period. Late filing attracts a penalty of S$200, with additional penalties of S$200 for each subsequent month of non-compliance, up to a maximum of S$10,000.

Common GST Compliance Pitfalls

Failing to Register on Time

If your taxable turnover exceeds S$1 million at the end of the calendar year and you do not apply for registration between 1 January and 30 January of the following year, IRAS may impose penalties and backdate your effective registration date. Similarly, if you fail to apply within 30 days under the prospective basis, IRAS may require you to account for GST retrospectively from the date you should have been registered.

Incorrect Tax Invoice Format

Issuing invoices that do not meet IRAS requirements can result in your customers being unable to claim input tax, which can damage business relationships.

Mixing Exempt and Taxable Supplies

If your business makes both exempt and taxable supplies, you must apportion your input tax claims correctly. This is known as the partial exemption method and requires careful calculation.

Poor Record-Keeping

IRAS requires GST-registered businesses to keep records for at least five years. Incomplete or inaccurate records can lead to penalties during audits.

How Nas Chartered Accountants Can Help

GST compliance can be complex, especially for growing businesses. At Nas Chartered Accountants, our Tax Advisory services include:

• GST Registration — We handle the entire registration process with IRAS
• Quarterly GST Filing — Preparation and submission of GST F5 returns
• Input Tax Optimisation — Ensuring you claim all eligible input tax credits
• GST Compliance Review — Identifying and resolving potential compliance issues
• IRAS Audit Support — Representation and support during IRAS audits

GST Registration and Filing is included in our Growth package (from S$2,400/year) and available as an add-on service for our Starter package.

Need help with GST? Book a free consultation with our tax advisory team to discuss your GST requirements.