GST Registration in Singapore: Thresholds and How to Apply (2026)

Registration is compulsory once your taxable turnover passes S$1 million, and voluntary registration now comes with an e-invoicing condition attached

Singapore’s Goods and Services Tax sits at 9%, and registering for it stops being optional once your business crosses S$1 million in taxable turnover. Below that line, registration is a choice with real trade-offs either way. This guide covers who must register, the two tests IRAS actually applies, the documents and steps involved, and the GST InvoiceNow condition that now comes attached to voluntary registration.

Quick Answers: Thresholds, Deadlines and Requirements

Question	Short Answer
When is GST registration compulsory?	Once your taxable turnover exceeds S$1 million, looking back over the past calendar year or forward over the next 12 months.
How long do I have to register?	30 days from the date your liability to register arose.
Can I register voluntarily below S$1 million?	Yes, but it requires a GIRO arrangement, an e-learning course, and in most cases GST InvoiceNow onboarding.
What happens if I register late?	You still owe the GST you should have charged from your true effective date, plus penalties, even if you never collected it.
How do I check if a business is GST-registered?	Search its name, UEN or GST number on the IRAS myTax Portal.

Businesses often treat the S$1 million line as the whole answer. It only tells you registration is required. Which test you fail, how your business is structured, and what you file alongside the application still decide what happens next.

Table of Contents

1. Is GST Registration Mandatory in Singapore?
2. Who Needs to Register for GST?
3. What Are the Requirements for GST Registration?
4. How to Register for GST in Singapore
5. How to Check If a Business Is GST-Registered
6. What Happens If You Don’t Register When Required?
7. What’s the Purpose of GST Registration?
8. Managing GST-Registered Spend and Records with YouBiz
9. FAQs

Is GST Registration Mandatory in Singapore?

Yes, once your taxable turnover crosses S$1 million. Below that line, registering is your choice.

Compulsory Registration: the S$1 Million Threshold

Taxable turnover is the total value of your business’s standard-rated supplies (charged at 9%) and zero-rated supplies (such as exports and international services, charged at 0%) made in Singapore. It excludes exempt supplies, such as most financial services and residential property rentals, as defined by IRAS.

IRAS assesses taxable turnover using two tests: one looks backwards at what your business has already billed, while the other looks forward at what you expect to bill. Businesses should monitor both tests throughout the year. If either test shows taxable turnover exceeding S$1 million, GST registration becomes compulsory. The next section explains how each test works.

Voluntary Registration: When It Makes Sense

If your taxable turnover is below S$1 million, you can still register for GST voluntarily. This can make sense if your customers are mostly GST-registered businesses, as they can generally claim back the GST you charge them as input tax. It can also be useful if your business incurs significant GST on its own purchases and wants to claim that back as input tax.

Voluntary registration may be less suitable if you mainly sell to consumers who cannot reclaim GST. In that case, you may need to either increase your prices by 9% or absorb the GST within your existing margins.

Voluntary registration also comes with these requirements, in addition to submitting the application:

1. GIRO arrangement: Set up a GIRO arrangement for paying and receiving GST refunds through the myTax Portal as part of your registration application.
   
   
2. “Overview of GST” e-learning course: A sole proprietor, partner, or company director must complete the 10-module course and retain the completion acknowledgement page for your records.
   
   
3. GST InvoiceNow onboarding: Businesses incorporated within 6 months of applying have been subject to this requirement since 1 November 2025. From 1 April 2026, it applies to all voluntary GST registrants, regardless of when they were incorporated or their business structure. Our GST InvoiceNow guide covers the full timeline, free solution packages and available grants.

Once approved, voluntary GST registration is binding for at least 2 years, so it is not something you can sign up for temporarily and reverse after a quarter.

Who Needs to Register for GST? (Compulsory Registration Rules)

Compulsory GST registration can be triggered by either of two tests. IRAS expects businesses to monitor both, rather than relying on whichever test is more convenient.

The Retrospective View: Looking Back at the Previous Calendar Year

The retrospective test looks at your taxable turnover for the calendar year, from 1 January to 31 December, and compares it with the S$1 million threshold. If your taxable turnover exceeds S$1 million, you become liable for GST registration.

You then have 30 days from the end of that calendar year to apply for registration, meaning the deadline is 30 January of the following year. Your GST registration takes effect from the first day of the third month after the end of the calendar year — 1 March.

Worked example: Your taxable turnover for the year ending 31 December 2026 comes to S$1.2 million. You must apply by 30 January 2027, and your GST registration takes effect from 1 March 2027.

The Prospective View: Looking Ahead 12 Months

The prospective test asks whether you can reasonably expect your taxable turnover to exceed S$1 million over the next 12 months. This expectation must be supported by firm evidence, such as signed contracts or confirmed orders, rather than a general business forecast.

The date on which you form that reasonable expectation is when your GST liability arises. You then have 30 days to apply for registration, and your registration takes effect 2 months after that date.

Worked example: An interior design firm has an existing contract worth S$900,000 and then signs a second contract worth S$925,000. Based on the unbilled value of both contracts over the next 12 months, the firm’s reasonably expected taxable turnover exceeds S$1 million on the day the second contract is signed. That is when its GST liability arises, so it must apply within 30 days, with registration taking effect 2 months after that date.

Both tests need to be monitored throughout the year. Crossing the S$1 million threshold under either test is enough to trigger compulsory GST registration, even if taxable turnover remains below S$1 million under the other test.

How Your Business Structure Affects the Threshold

How you calculate the S$1 million threshold depends on your business structure and how it is registered with ACRA:

• Company. Each company is assessed based on its own taxable turnover. If you own multiple companies, their turnovers are generally assessed separately because each is a separate legal entity. For example, if you operate two companies with S$500,000 in taxable turnover each, neither would cross the S$1 million threshold based on turnover alone.
  
  
• Sole proprietorship. IRAS looks at the combined taxable turnover of all sole proprietorship businesses you own, along with income from any other trade, profession or vocation, including freelance and commission income. For example, if your sole proprietorship has S$700,000 in taxable turnover and you earn another S$400,000 from freelance or commission work, your combined taxable turnover is S$1.1 million — even if the freelance work is not registered as a separate business.
  
  
• Partnership. IRAS combines the taxable turnover of partnership businesses with the same composition of partners. A partnership with a different set of partners is assessed separately, even if you are a partner in both.

Getting this calculation wrong can mean missing the point at which GST registration becomes compulsory. For example, a sole proprietor who tracks one business against the S$1 million threshold but leaves freelance or commission income out of the calculation could cross the threshold without realising it.

What Are the Requirements for GST Registration?

Documents You’ll Need

Before starting your GST registration application, have these documents and details ready:

• Financial statements or a turnover forecast. The supporting document you need depends on whether you are registering under the retrospective or prospective test.
  
  
• A list of sole proprietorship businesses you own, or confirmation that you do not own any.
  
  
• Supporting documents in PDF or XML format. Each file must be under 2 MB, with a total upload limit of 30 MB. For prospective registration, this may include signed contracts or purchase orders supporting your expected turnover.
  
  
• Corppass or Singpass access for the person submitting the application, along with your business’s UEN.

Incomplete information or missing supporting documents can result in your application being rejected or delayed. It’s worth gathering everything before you start the form, rather than having to stop halfway through to track down missing documents.

The GST InvoiceNow Condition on New Voluntary Registrations

The InvoiceNow requirement works differently depending on why you’re registering.

For compulsory registration, InvoiceNow is not an immediate condition of your GST application. Instead, businesses will be brought into the requirement progressively based on their annual turnover, with the compulsory phase-in running from 1 April 2028 to 1 April 2031.

For voluntary registration, the requirement can apply from the start. Since 1 April 2026, all new voluntary GST registrants must onboard an InvoiceNow-ready accounting solution as a condition of approval. Failing to comply can result in your GST registration being revoked.

Our GST InvoiceNow guide covers the full phase-in timeline, available free solution packages and transition grants.

How to Register for GST in Singapore (Step-by-Step)

GST registration applications are submitted online through the myTax Portal. IRAS reviews most applications within 10 working days, although some can take up to 30 days.

What happens after you submit: Save the acknowledgement page when your application is submitted, as it cannot be retrieved once you close the screen. IRAS may contact you by email or letter if it needs additional information. Once your application is approved, you’ll receive a notification letter containing your GST registration number and effective date. You should start charging GST from the effective date, not before.

How to Check If a Business Is GST-Registered

You can use IRAS’s GST Registered Business Search on the IRAS myTax Portal to check whether a business is GST-registered. Search by the business name, UEN or GST registration number. The service is free and does not require a login; business-name searches require at least five characters.

This is useful whether you’re buying or selling. As a customer, you can verify that a supplier is GST-registered before paying GST. As a business, you can check a supplier’s registration status before claiming input tax on its invoices.

Finding your own GST registration number: IRAS does not issue a separate certificate for download. Your GST registration number and effective date are stated in your registration notification letter. You can also view the letter under “Notices/Letters” in the myTax Portal, alongside the copy sent to your registered address.

What Does a GST Registration Number Looks Like?

Your GST registration number is a separate identifier from your UEN. It follows the format M + 8 digits + a check letter, for example, M91234567X.

A UEN follows a different format, such as 200312345A. While both identify your business for tax and administrative purposes, they are separate numbers. Your GST registration number is the one you’ll use on your tax invoices once you’re GST-registered.

What Happens If You Don’t Register When Required?

Failing to register when you’re required to doesn’t remove your GST liability. IRAS can backdate your registration and impose penalties for the period you were unregistered.

• Backdated GST. IRAS can backdate your GST registration to the date you should have registered. You’ll then owe GST on taxable supplies made from that date, including sales where you did not collect GST from customers at the time.
  
  
• Late-registration penalties. IRAS can impose a fine of up to S$10,000, plus a penalty of 10% of the GST due for each year or part of a year that you were late. A further S$50 per day may apply for an offence that continues after conviction.
  
  
• Prosecution. In serious or repeated cases, IRAS may pursue prosecution in addition to the backdated GST and applicable penalties.
  
  
• Wrongful collection is a separate offence. If you charge or collect GST before you’re registered, this is a separate offence. It can carry a fine of up to S$10,000 and a penalty of 3 times the GST amount shown on the invoice. Any GST collected wrongly must still be accounted for and paid to IRAS.

If you realise you’ve missed the registration threshold, don’t wait for IRAS to find it first. Register as soon as possible and disclose the late registration as part of your application. IRAS may take voluntary disclosure and other circumstances into account when determining penalties.

What’s the Purpose of GST Registration? (Input Tax vs Output Tax)

GST isn’t an extra source of income for your business. The GST you collect from customers, known as output tax, is generally payable to IRAS. Meanwhile, GST your business pays on eligible purchases, known as input tax, can generally be claimed back. The amount you ultimately pay to IRAS is the difference between your output tax and allowable input tax.

Here’s a simple supply-chain example:

Step	Price charged	GST at 9%	What it’s called
Manufacturer imports a leather bag for S$100	—	S$9	Manufacturer’s input tax
Manufacturer sells it to a retailer for S$200	S$200	S$18	Manufacturer’s output tax / retailer’s input tax
Retailer sells it to a consumer for S$300	S$300	S$27	Retailer’s output tax

The manufacturer collects S$18 in output tax and claims S$9 of input tax, so it pays S$9 to IRAS. The retailer collects S$27 in output tax and claims the manufacturer’s S$18 as input tax, so it also pays S$9.

Across the supply chain, IRAS ultimately receives the full S$27 of GST paid by the consumer, collected in stages rather than by one business.

When Can You Claim Input Tax?

To claim input tax, your business generally needs a valid tax invoice addressed to it. The purchase must also be for making taxable supplies and used for business purposes; input tax relating to exempt supplies or non-business activities may not be claimable.

For purchases of S$1,000 or less, including GST, a simplified tax invoice can generally be used. Purchases above S$1,000 require a full tax invoice, subject to the applicable GST invoicing rules.

Managing GST-Registered Spend and Records with YouBiz

Once your company is GST-registered, eligible business purchases can become input tax claims, while your records and invoices need to be properly maintained for GST reporting. Good spend records make both easier to manage.

What to check in your bookkeeping once you’re registered:

• Currency and amounts: Make sure purchases are recorded with the correct amount payable in Singapore dollars. Your GST return must be reported in SGD, even when the original purchase was made in another currency.
  
  
• Tax invoices: Keep spend categorised clearly enough for your accountant to identify purchases supported by valid tax invoices and determine which input tax claims are allowable.
  
  
• Record retention: Keep your GST records for the full 5-year retention period required by IRAS.

YouBiz gives GST-registered businesses a corporate Mastercard with real 0% FX fees on foreign card spend. Your transaction is converted using the applicable Mastercard wholesale exchange rate, without an additional foreign-currency card fee

Admins can lock individual cards to specific merchant categories, making it easier to separate travel, software and supplier spend when reviewing expenses. Statements can connect to Xero and be exported as CSV or XLS, so reconciling card transactions doesn’t mean manually re-entering figures from a PDF statement.

YouBiz does not file your GST return or transmit InvoiceNow data on your behalf — that’s handled by your accounting or InvoiceNow solution. Our GST InvoiceNow guide covers the accredited providers and requirements.

Instead, YouBiz helps keep business spend organised before it reaches your accountant, with 8 currency wallets (SGD, USD, EUR, GBP, JPY, HKD, AUD and CHF), unlimited 1% cashback on eligible spend and no monthly fee. More than 10,000 businesses use YouBiz to manage their business spend.

Applying takes under 5 minutes via Singpass. Applications are typically reviewed within 1 to 2 business days, with a virtual Mastercard available in the app after approval.

FAQs

GST Registration: What to Check Before You Apply

The S$1 million threshold determines whether GST registration is compulsory — not how easy GST is to manage once you’re registered. Check both the retrospective and prospective tests throughout the year, and make sure you’re calculating taxable turnover correctly for your business structure. If you’re registering voluntarily, factor in the GIRO arrangement, e-learning course and GST InvoiceNow onboarding before you apply.

Whichever route you take, keeping accurate records matters just as much as getting the registration right. YouBiz gives GST-registered businesses a multi-currency Mastercard with real 0% FX fees and unlimited 1% cashback on eligible spend. Statements can connect to Xero, making it easier to keep transaction records organised for your accountant from the start.

This guide provides general information and is not tax advice. GST thresholds, deadlines and penalties may change, so confirm your company’s position with IRAS or a qualified tax adviser before taking action.