GST Registration Singapore: When Do I Need to Register for GST?
When do you need to register for GST in Singapore? Learn the S$1m GST threshold, compulsory and voluntary registration rules, deadlines and how to apply.
GST Registration Singapore: When Do I Need to Register for GST?
If you run a growing SME in Singapore, you may eventually find yourself asking: “When do I need to register for GST?”
This is an important question because GST registration is compulsory once your business meets certain conditions. Missing the registration deadline can result in additional GST liabilities and penalties.
At the same time, not every company with S$1 million in revenue necessarily has to register immediately. Singapore's GST registration rules look at your taxable turnover, when the turnover was earned, and whether you can reasonably expect your business to cross the registration threshold in the coming 12 months.
This guide explains the GST registration requirements in Singapore, when an SME must register, how the S$1 million threshold works and what you need to prepare when completing your GST registration application.
What Is GST Registration in Singapore?
Goods and Services Tax (GST) is a consumption tax imposed on the supply of goods and services in Singapore and on the importation of goods.
Once your company becomes GST-registered, it generally has to charge GST on its taxable supplies. It must also submit GST returns to the Inland Revenue Authority of Singapore (IRAS) and account for the GST collected.
A GST-registered business may generally claim GST incurred on eligible business purchases and expenses, subject to the relevant input tax claiming conditions.
For an SME, however, the first question is usually much simpler:
When does my company actually have to register?
When Do I Need to Register for GST in Singapore?
The key number to remember is:
S$1 million in taxable turnover.
According to IRAS, a business is required to register for GST if:
Under the retrospective view, its taxable turnover was more than S$1 million at the end of a calendar year; or
Under the prospective view, it can reasonably expect its taxable turnover to be more than S$1 million in the next 12 months.
These two tests work differently, so SME owners should understand both.
What Does “Taxable Turnover” Mean?
One common mistake is to assume that the S$1 million GST registration threshold simply means your company's total accounting revenue.
That is not necessarily the case.
For GST registration purposes, taxable turnover generally refers to the value of taxable supplies made in Singapore in the course of your business.
It includes both:
Standard-rated supplies, such as most goods and services supplied locally; and
Zero-rated supplies, such as qualifying exports of goods and international services.
Certain amounts are excluded, including exempt supplies, out-of-scope supplies and the sale of capital assets.
Practical Example
Suppose an SME has the following transactions during the year:
Local taxable sales: S$850,000
Export sales that qualify as zero-rated supplies: S$250,000
Sale of an old company vehicle or other capital asset: S$50,000
The S$850,000 and S$250,000 would generally form part of taxable turnover, giving the business taxable turnover of S$1.1 million.
The sale of the capital asset would generally not be included when calculating the GST registration threshold.
This is why businesses approaching S$1 million should review the nature of their revenue, rather than relying solely on the revenue figure in their accounts.
GST Registration Test 1: The Retrospective View
The retrospective test looks backwards.
At the end of each calendar year — 31 December — you should determine whether your taxable turnover for the period from 1 January to 31 December exceeded S$1 million.
If it did, GST registration is generally compulsory.
For example, suppose ABC Pte. Ltd. had taxable turnover of:
S$780,000 in 2024
S$1.15 million from 1 January to 31 December 2025
The company crossed the S$1 million threshold for the 2025 calendar year.
Under the retrospective test, it would generally need to apply for GST registration between 1 January and 30 January 2026 and would be registered for GST from 1 March 2026.
An important point for SMEs is that the retrospective test is based on the calendar year, not necessarily your company's financial year.
For example, if your financial year ends on 30 June, you still need to consider your taxable turnover from 1 January to 31 December when applying this test.
Do I Have to Register Immediately When Sales Cross S$1 Million During the Year?
Not necessarily.
Suppose your taxable turnover crosses S$1 million in October. This does not automatically mean that you must immediately register under the retrospective test.
If you do not reasonably expect your taxable turnover to exceed S$1 million over the next 12 months, IRAS allows you to wait until the calendar year ends and assess whether registration is required under the retrospective rules.
However, you must separately consider the prospective test.
This distinction is important because many fast-growing SMEs may become liable for GST registration under the prospective test before the end of the calendar year.
GST Registration Test 2: The Prospective View
The prospective test looks forward rather than backward.
At any point in time, if your company can reasonably expect its taxable turnover to exceed S$1 million in the next 12 months, you may have a GST registration obligation.
The expectation should be supported by evidence.
Examples of evidence recognised by IRAS include:
Signed customer contracts or agreements;
Accepted quotations;
Confirmed purchase orders;
Customer invoices showing fixed recurring fees; and
Financial information showing that turnover is already approaching S$1 million and continues to increase.
A sales target or optimistic business forecast by itself does not necessarily mean you are required to register.
Practical Example
Imagine a Singapore SME currently has annual taxable turnover of S$700,000.
On 15 August, it signs a major 12-month customer contract. Based on the contract and its existing customers, the company can now reasonably expect more than S$1 million in taxable turnover over the next 12 months.
The company should assess its GST registration obligation from 15 August, even though it has not yet actually received S$1 million in sales.
For GST registration liabilities arising on or after 1 July 2025, the company must generally apply within 30 days of the date of its forecast, while its effective GST registration date will generally be two months from the forecast date.
The two-month period gives businesses more time to prepare their invoicing, accounting and operational systems before they have to start charging GST.
What If I Think Sales Might Exceed S$1 Million?
There is a difference between:
“We hope to make more than S$1 million.”
and
“Based on confirmed business, we can reasonably expect to make more than S$1 million.”
The prospective GST registration requirement is concerned with the second situation.
For example, internal budgets, market projections and ambitious sales targets may indicate that your business could cross S$1 million. However, IRAS states that a forecast without sufficient certainty — such as one based merely on market assessments, business plans or sales targets — does not by itself require GST registration under the prospective basis.
This is why SMEs should maintain proper documentation supporting their turnover forecasts.
Is There an Exception to Compulsory GST Registration?
There are limited situations where a business may not have to register even though the retrospective threshold has been crossed.
For example, a business that exceeded S$1 million under the retrospective test but is not liable under the prospective test may qualify for an exception where it is certain that taxable turnover will not exceed S$1 million in the next 12 months because of specific circumstances.
A possible example could be a substantial downsizing of the business.
The company must be able to support its position with appropriate documents and calculations.
Businesses whose taxable turnover consists wholly or mainly of zero-rated supplies may also be able to apply for exemption from GST registration.
These exceptions should be considered carefully rather than simply assuming that registration is unnecessary.
Can My SME Register for GST Voluntarily?
Yes.
If your company is not required to register compulsorily, you may still apply for voluntary GST registration, subject to IRAS's requirements.
There can be commercial reasons for doing so.
For example, a business that incurs substantial GST on business expenses may want the ability to claim eligible input tax. GST registration may also be less commercially sensitive for a predominantly business-to-business company whose customers are themselves GST-registered.
However, voluntary registration creates ongoing responsibilities.
Your company will need to account for GST, maintain proper records, file GST returns and comply with other GST requirements.
Voluntary registrants are also generally required to complete IRAS's “Overview of GST” e-learning course before applying.
Voluntary registration should therefore be a business decision, rather than something done simply because the company is approaching the S$1 million threshold.
GST InvoiceNow Requirements for New Voluntary Registrants
SMEs considering voluntary GST registration should also be aware of an important recent change.
Singapore is progressively introducing the GST InvoiceNow Requirement, under which GST-registered businesses will submit invoice data to IRAS using InvoiceNow-Ready Solutions.
For businesses applying for voluntary GST registration on or after 1 April 2026, the GST InvoiceNow Requirement applies regardless of incorporation date or business structure.
Before applying, an affected business will therefore need to:
Adopt an InvoiceNow-Ready accounting solution or make its existing system compatible;
Obtain a Peppol ID; and
Enable the GST InvoiceNow submission feature.
The requirement will progressively extend to other GST-registered businesses, including businesses applying for compulsory GST registration from 1 April 2028.
For SMEs considering voluntary registration, accounting system readiness should therefore form part of the decision-making process or you can engage Secroia to do the GST registration for your company.
How to Register for GST in Singapore
GST registration is submitted electronically through myTax Portal using the “Register for GST” digital service.
Before starting the application, IRAS recommends that businesses first determine whether registration is compulsory. IRAS also provides a GST Registration Calculator for this purpose.
The online application contains four main stages:
1. Declaration
The person submitting the application must confirm that the information provided is true and complete and acknowledge the company's responsibilities as a GST-registered business.
2. Main Form
This is the main part of the GST registration application.
Information requested may include:
Business profile;
Business activities;
Taxable supplies;
Imported services and low-value goods, where relevant;
Accounting period;
InvoiceNow information;
Questionnaire responses;
Supplies made before GST registration; and
Supporting documents.
3. Confirmation
Review the information carefully before submitting the application.
Incorrect or incomplete information can delay processing and may result in IRAS requesting additional documents.
4. Acknowledgement
After submitting the application, save a copy of the acknowledgement page.
IRAS specifically advises applicants to do this because the acknowledgement page will no longer be available for download after the page is closed.
What Documents Do I Need for GST Registration?
The documents required will depend on the company's circumstances and the answers given in the application.
For a Singapore-incorporated SME, it is sensible to prepare your documents before beginning.
Common documents may include:
The company's latest ACRA Business Profile;
Recent customer invoices;
Recent sales or revenue listings;
Contracts and confirmed purchase orders supporting future turnover;
Relevant licences, permits or approvals; and
Other documents supporting the information provided in the application.
Where invoices have already been issued, IRAS may request copies of three recent invoices (or all invoices if fewer than three have been issued) and a listing of sales or revenue for the previous two months.
Documents uploaded through the GST registration form generally need to be in PDF or XML format, with each file below 2 MB and the total attachments not exceeding 30 MB.
Having these records ready before starting can make the application significantly smoother.
A Practical GST Registration Checklist for SMEs
Before submitting your application, check the following:
Calculate your taxable turnover, rather than simply looking at accounting revenue.
Check the retrospective test using your taxable turnover from 1 January to 31 December.
Check the prospective test and consider whether confirmed contracts or orders mean turnover will exceed S$1 million in the next 12 months.
Identify your registration deadline if registration is compulsory.
Prepare supporting documents before opening the online application.
Check whether GST InvoiceNow applies to your company.
If registering voluntarily, complete the required GST e-learning course and understand the ongoing compliance requirements.
Do not charge GST before your GST registration has been approved.
That last point is particularly important. A business should not simply start adding GST to its invoices because it has submitted an application.
Common GST Registration Mistakes SMEs Should Avoid
A few practical mistakes can cause unnecessary problems.
Using total revenue instead of taxable turnover.
The S$1 million threshold relates to taxable turnover. Certain transactions may need to be excluded, while zero-rated supplies may still need to be included.
Only checking turnover at financial year-end.
The retrospective test uses the calendar year, while the prospective test can apply at any point during the year.
Ignoring confirmed future contracts.
A company can become liable for registration before it has actually earned S$1 million if there is sufficient certainty that taxable turnover will exceed the threshold in the next 12 months.
Waiting until the last minute to gather supporting documents.
IRAS may require invoices, sales listings, contracts and other evidence. Preparing them early makes the application easier.
Charging GST before registration is approved.
Submitting a GST application does not automatically entitle a company to start collecting GST.
Frequently Asked Questions About GST Registration Singapore
When do I need to register for GST in Singapore?
Generally, you must register if your taxable turnover exceeds S$1 million for the calendar year under the retrospective test, or if you can reasonably expect taxable turnover to exceed S$1 million in the next 12 months under the prospective test.
What is the GST registration threshold in Singapore?
The compulsory GST registration threshold is more than S$1 million in taxable turnover.
Is the S$1 million GST threshold based on revenue or profit?
It is based on taxable turnover, not profit. A company can therefore be loss-making and still have a GST registration obligation.
Is the GST threshold based on my company's financial year?
For the retrospective test, taxable turnover is assessed for the calendar year from 1 January to 31 December, regardless of your company's financial year-end.
Can I voluntarily register for GST if my turnover is below S$1 million?
Yes, subject to satisfying IRAS's voluntary registration requirements. However, you should consider the costs and ongoing responsibilities before applying.
Can I charge GST while waiting for IRAS to approve my application?
No. IRAS states that businesses should not collect GST before GST registration is approved.
How often should an SME check whether GST registration is required?
At a minimum, review taxable turnover at the end of every calendar year. Growing SMEs should monitor it more frequently because the prospective test can apply at any point when there is sufficient certainty that taxable turnover will exceed S$1 million over the next 12 months.
Conclusion: Monitor GST Registration Before You Cross the Threshold
For Singapore SMEs, GST registration should not be something considered only after sales have already passed S$1 million.
The key is to monitor both your actual taxable turnover and your reasonably expected turnover for the next 12 months.
If your company is growing quickly, has recently signed a large contract or is approaching S$1 million in taxable turnover, reviewing your GST position early gives you time to prepare your accounting system, pricing, invoices and supporting documentation.
GST registration itself is only the beginning. Once registered, your company will also need processes for charging GST correctly, maintaining supporting records, claiming eligible input tax and filing GST returns.
If you are unsure whether your company has reached the GST registration threshold, or would like assistance preparing and submitting your GST registration application, consider speaking with your corporate services or accounting provider before the registration deadline.
This article provides general information on GST registration in Singapore and does not constitute tax advice. GST requirements may change and businesses should refer to the latest IRAS guidance or obtain professional advice for their specific circumstances.