Most directors know there is a GST threshold and that it sits at a million dollars. Fewer know there are two separate tests, that one of them looks forward rather than back, and that the forward-looking one can require you to register before you have earned the money.
The threshold
Registration becomes compulsory once your taxable turnover exceeds S$1 million. Taxable turnover means the total value of your taxable supplies made in Singapore — standard-rated and zero-rated — not your profit, and not every line on your invoice ledger.
Test one: looking back
If your taxable turnover for the calendar year exceeded S$1 million, you must apply for registration between 1 and 30 January of the following year, and you will be registered with effect from 1 March. This is the test most people have in mind, and it is the more forgiving of the two because the number is already known.
Test two: looking forward
At any point, if you can reasonably expect your taxable turnover to exceed S$1 million over the next twelve months, you must apply within 30 days of forming that expectation — and you need documentation supporting the forecast.
This is the one that catches growing companies. A signed contract, a confirmed order book or a funding round can create the expectation. The clock then runs from the date of the forecast, not from the date the revenue lands.
Registering voluntarily
You can register before you are required to. Whether you should depends on who your customers are.
- If you sell mainly to other GST-registered businesses, registering lets you claim input tax on your own costs while your customers reclaim what you charge them. The GST is broadly neutral to them.
- If you sell mainly to consumers, registering makes you 9% more expensive or 9% less profitable, depending on whether you raise prices. That is a commercial decision, not an accounting one.
Either way, registration brings ongoing obligations — returns, records and correct treatment of every transaction. It is not a one-off form.
What changes once you are registered
- You charge GST on your taxable supplies and issue compliant tax invoices
- You file GST returns on your assigned cycle, on time, including nil returns
- You keep records to support every figure you report
- Your invoicing and bookkeeping need to handle GST correctly from day one of registration, not from when you get around to it
The practical point
Monitoring the threshold is a bookkeeping function, not an annual one. If your accounts are only assembled at year end, you will discover you crossed the line months after the 30-day forward test would have required you to act. That is the argument for keeping the books current — it is what makes the threshold visible before it becomes a problem.
This article is general information about Singapore tax requirements, current at the date of publication. It is not tax advice, and thresholds, rates and registration rules are set by IRAS and change from time to time. Verify your own position with IRAS, or speak to us about your specific circumstances.