GST registration in Singapore: when and how

What GST is, in one line

GST is Singapore's goods and services tax. Once your company is registered, you charge it on your taxable sales and account for it to the tax authority, IRAS. The prevailing rate is 9%, which applies from 1 January 2024.

When registration is compulsory

IRAS applies two tests, and you must register if you meet either of them.

• Looking back. Your taxable turnover for the calendar year, 1 January to 31 December, was more than S$1 million. You apply between 1 and 30 January of the following year, and you are registered from 1 March. For example, if turnover went over S$1 million in 2025, you apply in January 2026 and register from 1 March 2026.
• Looking ahead. You expect your taxable turnover to be more than S$1 million in the next 12 months. You must apply within 30 days of the date of the forecast. For a forecast made on or after 1 July 2025, registration takes effect two months from the forecast date.

Taxable turnover means the total value of your taxable supplies made in Singapore, including standard-rated and zero-rated sales. It leaves out exempt supplies, out-of-scope supplies and sales of capital assets.

The forward-looking test needs evidence

A forecast only counts when there is certainty behind it. IRAS lists examples such as signed contracts, accepted quotations or confirmed purchase orders, invoices with fixed monthly fees, and income statements showing the past 12 months close to S$1 million with a rising trend. Forecasts based only on market assessments, business plans or sales targets do not count.

What happens if you register late

Late registration is backdated to the date you should have registered. You then have to account for GST on your past sales from that date, even if you never charged it. IRAS states that a fine of up to S$10,000 and a penalty of 10% of the GST due may apply. If you tell IRAS about the lateness when you apply, the fine and penalty are generally waived, but the backdating and the GST on past sales still apply.

Registering voluntarily

If you are below the threshold, you may still register. IRAS lists businesses that make taxable supplies, businesses that make only out-of-scope supplies, and certain others. The main reasons people consider it are claiming GST paid on purchases and not having to watch turnover as it nears S$1 million. The trade-offs are real: you must stay registered for 2 years, you act as a GST collecting agent, and IRAS warns that meeting these duties can increase your administrative costs. Voluntary applicants also need a GIRO arrangement for payments and, in many cases, must complete IRAS's "Overview of GST" e-learning course.

How the application works

Applications are made online on IRAS's myTax Portal. You attach supporting documents at the end, so prepare soft copies first. IRAS states that it processes 60% of applications within 10 working days and the rest within 30 days, and it does not process applications with incomplete information. When approved, IRAS sends a letter with your GST registration number and effective date. Print the number on your invoices and start charging GST from the effective date, not before.

How we help

We handle GST registration for Singapore companies: working out whether and when you must register, preparing the application, and keeping an eye on your turnover so you do not miss a due date.