How GST Works in Singapore for Small Businesses

What GST is and how it works

GST (Goods and Services Tax) is a consumption tax charged on most goods and services sold in Singapore, as well as on the import of goods. It is administered by the Inland Revenue Authority of Singapore (IRAS).

If you are GST-registered, you add GST to the price of what you sell (this is your output tax) and you can generally claim back the GST you paid on business purchases and expenses (your input tax). You pay IRAS the difference — output tax minus input tax — or receive a refund if your input tax is higher.

Because the tax is ultimately borne by the final customer, being GST-registered mostly makes your business a collector of GST on IRAS's behalf. Getting the mechanics right — charging the correct rate, keeping tax invoices, and claiming only eligible input tax — is what keeps you compliant.

This is general information — confirm current rules with IRAS or a qualified local tax professional before making decisions.

The current GST rate

The standard GST rate in Singapore is 9%. This applies to most local sales of goods and services (known as standard-rated supplies).

Some supplies are treated differently: exports of goods and certain international services are zero-rated (GST charged at 0%), while things like most financial services and the sale or lease of residential property are exempt (no GST charged, and input tax on related costs is generally not claimable).

• Standard-rated: most local goods and services — 9%.
• Zero-rated: exports and qualifying international services — 0%.
• Exempt: most financial services and residential property — no GST charged.
• Out of scope: sales that fall outside Singapore's GST rules altogether.

Who must register for GST

Registration is compulsory once your taxable turnover crosses the S$1,000,000 threshold. There are two tests to watch:

Under the retrospective test, you must register if your taxable turnover for the past 12 months was more than S$1,000,000. Under the prospective test, you must register if you can reasonably expect your taxable turnover for the next 12 months to exceed S$1,000,000 — for example, after signing a large contract.

You can also register voluntarily below the threshold, which lets you claim input tax but commits you to staying registered for a minimum period and meeting all the filing obligations. Weigh this carefully — it adds admin, so it usually only makes sense if you sell mainly to other GST-registered businesses or make zero-rated exports.

• Retrospective test: past 12 months' taxable turnover exceeds S$1,000,000.
• Prospective test: you reasonably expect the next 12 months to exceed S$1,000,000.
• Voluntary registration is possible below the threshold, with conditions.
• Once registered, IRAS issues you a GST registration number to show on tax invoices.

How to register

1. 1

   Check your turnover

   Add up your taxable turnover for the past 12 months and forecast the next 12. If either crosses S$1,000,000, registration is compulsory and time-sensitive.

2. 2

   Complete e-Learning if required

   IRAS asks some applicants (especially voluntary registrants) to complete a short GST e-Learning course before applying. Check whether it applies to you.

3. 3

   Apply through myTax Portal

   Submit your GST registration application online via IRAS's myTax Portal, with your business details and supporting documents.

4. 4

   Receive your GST registration number

   Once approved, IRAS confirms your effective date of registration and your GST registration number. From that date you must charge GST and issue proper tax invoices.

Filing the GST F5 return

GST-registered businesses report GST to IRAS on the GST F5 return. Most businesses file quarterly, though some are on monthly accounting periods. You must file a GST F5 for every period — even a 'nil' return if you had no transactions.

The return is due, together with any payment, within one month after the end of each accounting period. On it you declare your total sales, standard-rated supplies, output tax charged, and the input tax you are claiming.

Late filing or late payment can attract penalties, so it pays to reconcile your books and set aside the GST you collect rather than treating it as cash flow.

• File the GST F5 for each accounting period (commonly quarterly).
• Both the return and payment are due within one month of the period end.
• Nil returns are still required if you had no activity.
• Keep tax invoices and records for at least five years to support your figures.

E-invoicing with InvoiceNow

InvoiceNow is Singapore's national e-invoicing network, run on the international Peppol standard. It lets businesses send structured invoices directly from one accounting system to another, instead of emailing PDFs or paper.

IRAS is progressively adopting InvoiceNow for GST-registered businesses, so that transaction data flows to IRAS as part of e-invoicing. The rollout is being phased in — newly incorporated and newly GST-registered businesses are among the earlier groups — so check the timeline that applies to your situation.

Practically, this means your invoicing tool should be able to connect to an InvoiceNow-ready (Peppol) access point. Getting set up early smooths the transition and reduces manual data entry.

This is general information — confirm the current InvoiceNow requirements and dates with IRAS or a qualified local tax professional.

Staying organised with the right tools

The admin side of GST — charging the correct rate, issuing compliant tax invoices, tracking input tax, and preparing the GST F5 — is far easier when your sales, purchases, and accounting live in one place.

Tallium is an all-in-one accounting, POS, inventory, and e-commerce platform built for small and medium businesses. It handles GST on every sale, scans expense receipts, keeps your records tidy, and produces the reports you need to complete your GST F5. Plans are billed monthly per unit in US dollars — the shop/store unit is $79/month, an online store is $159/month, a warehouse is $99/month, and a factory is $269/month — paid from signup, cancel anytime. Every unit includes the full core: accounting, tax handling, expenses, reports, the mobile app, AI insights, and email support at support@tallium.online.

Tallium does not replace professional tax advice, but it keeps your books accurate so filing your return is quick and stress-free.