StartBiz SG

GST Registration Checker (IRAS S$1m Threshold)

Updated 25 Oct 2026 · StartBiz SG Editorial Team
Short answer

Enter your past calendar-year turnover and your expected next-12-months turnover. If either exceeds S$1 million you must register for GST — under the retrospective or the prospective test. Below the threshold, registration is voluntary. The prevailing GST rate is 9%.

On this page (4 sections)

Enter two turnover figures and this tool tells you whether GST registration is compulsory or voluntary under IRAS’s rules.

Tool

GST registration checker

Your standard-rated and zero-rated supplies for 1 Jan–31 Dec last year.

What you can reasonably expect over the coming 12 months (e.g. after a large contract).

GST registration is not compulsory — you may register voluntarily.

Neither test is met: your past-year turnover and your expected next-12-months turnover are both at or below S$1 million. You can still register voluntarily to claim input GST, subject to IRAS conditions (minimum registration period and compliance/e-invoicing duties).

Threshold: S$1,000,000 taxable turnover; prevailing GST rate 9%. Estimate only — confirm with IRAS before registering.

Based on IRAS — Do I need to register for GST. As of October 2026.

How it is calculated

IRAS applies two tests against a single S$1 million taxable-turnover threshold, and you check both:

  • Retrospective test: at the end of the calendar year, was your taxable turnover more than S$1 million? If yes, registration is compulsory — apply by 30 January of the following year, effective 1 March.
  • Prospective test: can you reasonably expect taxable turnover to exceed S$1 million in the next 12 months? If yes, apply within 30 days of forming that expectation.

If neither is met, registration is voluntary. (Source: IRAS — Do I need to register for GST.)

Worked example (illustrative)

A business had S$850,000 of taxable turnover last calendar year, so the retrospective test is not met. It then signs contracts making S$1.2 million likely over the next 12 months — the prospective test is now met, so it must apply for GST registration within 30 days of forming that expectation.

Limits of this estimate

This checks only the standard S$1 million turnover tests. It does not cover reverse-charge or overseas-vendor registration rules, the specific definition of your supplies, exemptions, or whether you should register voluntarily for input-tax recovery. “Taxable turnover” must be computed correctly (standard-rated and zero-rated supplies). Confirm your position and effective date with IRAS.

Sources

  1. Do I need to register for GST — Inland Revenue Authority of Singapore (as of October 2026)