What is the GST registration threshold?
The GST registration threshold is the level of taxable turnover at which a Singapore business must register for GST. The threshold is S$1 million in taxable turnover. IRAS applies two tests — retrospective and prospective — and you must register under the first one that's triggered.
The retrospective test
At the end of each calendar year (1 January to 31 December), check whether your taxable turnover for that year exceeded S$1 million.
If it did, you must apply for GST registration between 1 January and 30 January of the following year.
The prospective test
At any point in time, if you can reasonably expect taxable turnover to exceed S$1 million in the next 12 months (e.g. you just signed a large contract, your run-rate has jumped, you've acquired a competitor), you must apply for GST registration within 30 days of that forecast date. You'll be registered on the 31st day after the forecast date.
For prospective-basis liabilities arising on or after 1 July 2025, IRAS grants a two-month grace period before you need to start charging GST. That window exists so newly registered businesses can update systems, contracts and pricing.
What counts as "taxable turnover"
Taxable turnover includes:
- Standard-rated supplies (your local sales at 9%)
- Zero-rated supplies (exports, international services)
It excludes:
- Exempt supplies (most financial services, sale/lease of residential property)
- Out-of-scope supplies (e.g. third-country sales of goods)
- Sale of capital assets
Voluntary registration
If your turnover is below the S$1 million threshold, you may still register voluntarily. This usually makes sense if:
- Your customers are GST-registered businesses who can claim back the GST you charge them (so the GST is neutral to them)
- You have significant input tax on local purchases or imports that you'd like to reclaim
- You expect to cross the threshold soon and want to avoid a mid-year scramble
Voluntary registrants now sit inside the GST InvoiceNow Requirement's post-April-2026 scope — relevant if you're considering when to register.
Penalties for late registration
If you should have registered but didn't, IRAS can backdate your registration to the date you became liable, charge GST on supplies made since then (out of your own pocket if you didn't charge it), plus penalties. The retrospective+prospective tests exist so it's hard to genuinely "not notice" — keep your taxable turnover under monthly review near the threshold.
Related terms
- GST (Goods and Services Tax) — GST is Singapore's broad-based consumption tax — currently 9% — charged on most goods, services and imports.
- GST F5 — GST F5 is the quarterly GST return every GST-registered business in Singapore files with IRAS.
- Input tax vs output tax — Output tax is the GST you charge customers on sales.
- Uen (coming soon)
Sources
Last reviewed 29 May 2026. Verify any thresholds or dates against the official source above before relying on them.