It is on taxable turnover; exempt supplies (like residential rent) do not count.
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BANKING & TAX
When GST registration is required
Short answer
Taxable turnover over S$1 million requires GST registration (rate 9%), tested two ways. Below the threshold, registration is voluntary. Retrospective: if turnover over the past 12 months exceeds S$1M at any calendar year-end, apply within 30 days. Prospective: if you reasonably expect the next 12 months to exceed S$1M (e.g. a signed large contract), also apply within 30 days; for liabilities arising on or after 1 July 2025, registration takes effect 2 months after the date the expectation arose. From April 2026, all new voluntary registrants must use the InvoiceNow e-invoicing system.
Threshold and deadlines
| Test | Trigger | Deadline |
|---|---|---|
| Retrospective | At any calendar year-end, past 12 months' taxable turnover > S$1M | Apply within 30 days of year-end |
| Prospective | Reasonably expect next 12 months > S$1M (e.g. signed contract) | Apply within 30 days of forming that expectation; registration effective 2 months after that date (rule from 1 July 2025) |
| Voluntary | Below S$1M | Optional, must stay registered ≥2 years |
| GST rate | 9% (since January 2024) | |
Retrospective vs prospective
Retrospective: looks back. At each calendar year-end (Jan-Dec), review the past 12 months' taxable turnover; if over S$1M, apply within 30 days. Example: 2026 taxable turnover of S$1.1M means applying by 30 January 2027, with registration effective 1 March.
Prospective: looks forward. If you reasonably expect the next 12 months to exceed S$1M — typically after signing a contract that alone crosses the threshold — apply within 30 days of forming that expectation. Where the prospective liability arises on or after 1 July 2025, registration takes effect 2 months after the date the expectation arose (previously the 31st day). IRAS's test is whether you "reasonably expect" to exceed the threshold, and it expects documents supporting that expectation — for example signed contracts or agreements, accepted quotations or confirmed orders, invoices for fixed monthly fees, or revenue statements showing turnover already close to S$1M over the past 12 months. (Source: IRAS, verified 2026-09)
What "taxable turnover" means
The threshold is on taxable turnover, not total revenue. Taxable turnover is supplies that would attract GST if you were registered — standard-rated and zero-rated supplies — but not exempt supplies (like residential rent or certain financial services). Knowing what counts is essential to judge whether you must register.
The 2026 InvoiceNow rule
The key recent change: from April 2026, all new voluntary GST registrants must transmit invoice data to IRAS through the InvoiceNow (Peppol) network. The full schedule: from 1 November 2025, companies registering voluntarily within 6 months of incorporation; from 1 April 2026, all new voluntary registration applicants; from 1 April 2028, new compulsory registrants and existing GST businesses with annual supplies ≤ S$200,000; from 1 April 2029, ≤ S$1M; from 1 April 2030, ≤ S$4M; from 1 April 2031, > S$4M (i.e. everyone). Annual supplies are based on the amount reported for calendar year 2025. (Source: IRAS, verified 2026-09) If you plan to register voluntarily, prepare InvoiceNow-ready accounting software early.
Is voluntary registration worth it
You can register voluntarily below the threshold. The benefit is claiming input tax — useful if your customers are mostly GST-registered. But note two things: once voluntarily registered you must stay for at least 2 years; and from April 2026 voluntary registration means InvoiceNow. Whether it's worth it depends on your customer mix and compliance cost.
Common misconceptions
There is a 30-day deadline. Late, IRAS backdates registration to the date you should have registered, recovers GST you never collected, and may impose a fine of up to S$10,000 plus a penalty of 10% of the GST due.
From April 2026 voluntary registration requires InvoiceNow and a 2-year minimum.
How we handle it
We judge whether taxable turnover crosses the threshold, whether the retrospective or prospective test applies, when you must file, and whether voluntary registration is worth it and how to prepare InvoiceNow. See company registration; annual tax duties in what every company must do each year.
Frequently asked
At what turnover must I register for GST?
Taxable turnover over S$1M. Two tests — retrospective (past 12 months) and prospective (expected next 12 months) — with 30 days to apply after triggering.
What is the GST rate?
9%, since January 2024 (previously raised in two stages from 7% to 8% then 9%).
Can I register below the threshold?
Yes, voluntarily — you can claim input tax, useful if customers are GST-registered. But you must stay ≥2 years, and from April 2026 must use InvoiceNow.
What is InvoiceNow and who does it affect?
IRAS's e-invoicing system (Peppol network). From April 2026 all new voluntary registration applicants must use it, then it phases in: April 2028 (new compulsory registrants and existing businesses with supplies ≤ S$200,000), April 2029 (≤ S$1M), April 2030 (≤ S$4M), April 2031 (all GST businesses).
What if I miss the deadline after crossing?
There is a 30-day window. Late, IRAS backdates registration to the date you should have registered; you must account for GST on past sales even if you never charged it, and may face a fine of up to S$10,000 plus a penalty of 10% of the GST due, or prosecution.
Sources: IRAS (GST thresholds, retrospective/prospective tests, 9% rate, phased InvoiceNow). Verified July 2026; the full InvoiceNow schedule, prospective registration effective date, supporting documents and late-registration penalties re-checked against IRAS in 2026-09; follow IRAS's latest. General information, not tax advice.
Unsure whether to register for GST?
Whether turnover crosses the threshold, which test applies and when to file — we judge it, and assess whether voluntary registration is worth it.
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