GST registration Singapore: the S$1 million threshold

GST registration in Singapore is compulsory if your taxable turnover is more than S$1 million at the end of a calendar year, or if you can reasonably expect it to be more than S$1 million in the next 12 months. IRAS assesses these separately, as its retrospective and prospective views: the year-end test gives you 1 to 30 January to apply, while the forecast test starts a 30-day clock on the date of your forecast.

This guide works through both with dates for the 2026 year-end, the two exceptions, a monthly tracker you can copy and the points to weigh before registering early. It is general information, not tax advice.

What counts towards the S$1 million?

IRAS tests taxable turnover, not sales. Taxable turnover is the total value of taxable supplies made in Singapore in the course or furtherance of business: standard-rated supplies (such as local sales of goods or services) and zero-rated supplies (such as exports and international services; see our zero-rating guide). It leaves out exempt supplies, out-of-scope supplies and sales of capital assets such as machinery, equipment or furniture.

Businesses are combined by structure:

• Sole proprietors add up every sole proprietorship, including home-based businesses and commercial property rental, plus income from a trade or vocation such as driving a taxi or freelancing. IRAS’s example: S$500,000 + S$490,000 + S$30,000 of taxi income over the past 12 months is S$1,020,000, which exceeds S$1 million. IRAS adds that this person must register immediately if they can reasonably expect more than S$1 million over the next 12 months.
• Partnerships combine the businesses that have the same partners; a business with different partners is counted separately.
• Companies count their own turnover plus any sole proprietorships the company owns.

IRAS may disregard a split of one business into several entities if the purpose or effect is to avoid registration, and register the whole business from the date you became liable.

This guide covers only the S$1 million test: IRAS says its reverse charge and overseas vendor registration regimes can also require registration.

When does the year-end (retrospective) test apply?

Add up taxable turnover for 1 January to 31 December. If it is more than S$1 million, apply between 1 and 30 January of the following year; you are registered on 1 March. IRAS’s example uses 2025 turnover, with applications from 1 to 30 January 2026 and registration on 1 March 2026. The same pattern for 2026 gives 1 to 30 January 2027 and 1 March 2027.

Note that 30 January 2027 is a Saturday. IRAS’s page does not say whether a weekend end date moves. Treating Friday 29 January as the last day is our cautious suggestion, not IRAS guidance.

Passing S$1 million part-way through a year is not an immediate trigger. If you do not reasonably expect more than S$1 million in the next 12 months, IRAS says you can wait until the year ends and apply in January, or register voluntarily at any time.

When does the forecast (prospective) test start the clock?

If at any point you can reasonably expect taxable turnover above S$1 million in the next 12 months, you must apply within 30 days after the date of your forecast. For forecasts on or after 1 July 2025, registration takes effect 2 months from the forecast date instead of the 31st day; the 30-day application deadline did not change.

The test turns on evidence, not ambition. IRAS says you must hold documents that support the forecast, for example:

• signed contracts or agreements;
• accepted quotations or confirmed purchase orders;
• invoices to customers with a fixed monthly fee;
• income statements showing the past 12 months already close to S$1 million, with turnover on an increasing trend.

IRAS also says you are not required to register if there is no certainty in your forecast, for example one made from market assessment, business plans or sales targets. Evidence matters for a second reason: in an example in IRAS’s InvoiceNow FAQ, a business applied for compulsory registration on 15 April 2026 but could not document its S$1 million forecast, so it was registered as a voluntary registrant and had to comply with the GST InvoiceNow Requirement. Keeping forecast documents dated and together is our suggestion, not an IRAS rule; our guide to how long to keep business records covers retention.

A dated calendar for the 2026 year-end

These dates are illustrative: we applied IRAS’s rules to invented forecast dates. Our arithmetic (30 days after the forecast date to apply; two months after the forecast date, or the last day of a shorter month, to register) reproduces IRAS’s five dated examples for forecasts on or after 1 July 2025. Confirm your own dates with IRAS. Our free GST registration threshold checker tests both views and shows the apply-by and registration dates; where IRAS’s pages are silent it says to ask IRAS.

• Year-end test, calendar year 2026 above S$1 million: apply 1 to 30 January 2027; registered 1 March 2027.
• Signed contract above S$1 million on 2 November 2026: apply by 2 December 2026; registered 2 January 2027.
• Quotation accepted or purchase order confirmed on 30 November 2026: apply by 30 December 2026; registered 30 January 2027.
• Income statements show the past 12 months close to S$1 million and rising, and a forecast above S$1 million is made on 15 December 2026: apply by 14 January 2027; registered 15 February 2027, the same pattern as IRAS’s 15 January 2026 example.
• Tender worth more than S$1 million secured on 31 December 2026: apply by 30 January 2027; registered 28 February 2027, following IRAS’s 31 December 2025 tender example.

In these dates every forecast route takes effect before 1 March 2027, the year-end test’s date. Our inference is that a documented forecast can bring registration forward, which is why the tracker below records both views.

A monthly tracker you can copy

Record these at each month-end:

1. Taxable supplies this month: standard-rated plus zero-rated. Leave out exempt supplies, out-of-scope supplies and sales of capital assets.
2. Calendar year to date (the year-end test; it restarts on 1 January).
3. Last 12 months, and whether it rose again. This is our aid, not an IRAS test: it shows when the income-statement evidence above may become arguable.
4. Documents that could support a forecast, with their dates and the amounts expected within 12 months.
5. Turnover of related businesses you must combine.

Illustrative run (fictional). A commercial-cleaning company’s monthly taxable turnover rises from S$70,000 in January 2026 to S$108,000 in December, after S$60,000 to S$64,000 a month in late 2025. The figures leave out a S$30,000 van sale in August, a capital asset. The tracker reads:

• 30 September 2026: calendar year to date S$738,000; last 12 months S$924,000.
• 31 October 2026: S$834,000; S$960,000.
• 30 November 2026: S$938,000; S$1,002,000.
• 31 December 2026: S$1,046,000; S$1,046,000.

Only the 31 December reading triggers the year-end test: S$1,046,000 is above S$1 million, so, unless a forecast liability arose earlier, the company applies between 1 and 30 January 2027 and is registered on 1 March 2027. The rolling figure passing S$1 million on 30 November is not a year-end trigger. Our inference: a rolling figure already above S$1 million and still rising resembles IRAS’s income-statement example, so the company may have had a forecast date before 31 December. IRAS does not define “close to S$1 million” for that example, and whether such a date arose is a judgement for the owner, an adviser or IRAS.

Can you avoid registering?

IRAS describes two exceptions, and both need paperwork.

• Mostly zero-rated supplies. You may apply for exemption from registration if zero-rated supplies are more than 90% of total taxable supplies and you would be in a net refundable position had you been registered. Once approved, you charge no GST and file no returns, but cannot claim GST on purchases. IRAS says you must keep monitoring; if you stop qualifying and your annual taxable turnover exceeds S$1 million, you must notify IRAS within 30 days.
• Year-end test met, forecast test not met. You need not register if you are certain next-12-month taxable turnover will not exceed S$1 million because of specific circumstances IRAS lists: the expiry or termination of a high-value sales contract with a major customer (with new contracts unlikely in the next 12 months), large-scale downsizing, revocation of a business licence or termination of sales distribution rights, or cessation of all business activities. You must hold documentary evidence and a detailed computation, and keep monitoring turnover at the end of the next calendar year.

What happens if you register late?

GST is self-assessed, so the duty to monitor is yours. Under IRAS’s late-notification rules, your registration date is backdated to when you ought to have registered, and you must account for GST on past sales from then even if you did not collect it. You may face a fine of up to S$10,000 and a penalty of 10% of the GST due, and prosecution may apply.

If you disclose that you are late when you apply, IRAS says it will generally waive the fine and penalties. You still owe the GST, though you may be allowed to pay in instalments.

Should you register voluntarily before the threshold?

IRAS lets a business with taxable supplies register voluntarily, and its page on factors to consider (last updated 30 January 2026) sets out the trade-offs. This list pulls them together; it does not recommend either choice.

• Two years in. Voluntary registrants must stay registered for 2 years, so IRAS suggests weighing costs and benefits over that period.
• Suppliers and customers. You can generally claim GST on purchases from GST-registered suppliers, subject to IRAS’s conditions; unregistered suppliers should charge none, so there is nothing to claim. GST-registered customers may be able to claim what you charge; if yours are not and you must keep your price, IRAS’s Example 3 shows GST of S$16.51 (9/109 of S$200) cutting gross profit on a S$200 sale from S$100 to S$83.49.
• Zero-rated sales. If your supplies qualify for zero-rating, such as exports, IRAS’s Example 4 shows gross profit on a S$200 sale rising from S$91 to S$100 because you can claim the S$9 of GST on a S$109 purchase.
• InvoiceNow. From 1 April 2026 every business that applies for new voluntary registration must meet the GST InvoiceNow Requirement, and IRAS’s FAQ says an application may not be approved, or registration may be revoked, if you do not comply. The same FAQ says free InvoiceNow-Ready software is available to SMEs until March 2031; check what it covers. Our InvoiceNow adoption plan and summary of IRAS’s FAQ explain it.
• Process. IRAS’s application steps require voluntary registrants to submit a GIRO application and to complete the “Overview of GST” e-Learning course and quiz, unless an exception applies. IRAS says it processes 60% of applications within 10 working days and the rest within 30 days.

What to check before you apply

1. Which test applies, and the date: the calendar-year total or a dated forecast.
2. Whether related businesses must be combined with yours.
3. Your application deadline and effective date, written in a calendar.
4. That you do not charge GST because you applied. IRAS says to charge only from the effective date; the approval letter gives the GST registration number to print on invoices, credit notes and receipts.
5. How quotes and invoices will change: see our worked examples of GST on quotes and invoices, and the sales topic hub for related guides.

Common questions