Voluntary GST Registration In 2026: Trusted Guide You Need

Q: Can I claim GST on past business expenses?

Yes, you may be allowed to claim input GST on eligible pre-registration expenses made within 6 months before your GST effective date. However, these expenses must be directly related to your business’s taxable supplies. IRAS also requires full documentation, including valid tax invoices, to approve such claims.

Lydia Chin

7 mins read

Published:

11 June 2025

Updated:

18 February 2026

Want to register GST voluntarily?

Voluntary GST registration in Singapore can be confusing, time-consuming, and costly if done at the wrong stage.

Many small business owners feel unsure about whether it’s worth the admin burden, fear losing customers by charging the Goods and Services Tax (GST), or worry they’ll miss out on tax benefits if they don’t act early.

In this guide, we break down the real numbers, the risks, and the benefits to help you make an informed decision.

What is voluntary GST registration?

Voluntary GST registration in Singapore means a business chooses to register for GST even if its annual taxable turnover is below S$1 million. Registered businesses must charge 9% GST, file quarterly returns, and comply with all GST obligations. The commitment lasts for a minimum of two years.

How it works and who’s eligible (2026)

In 2026, the GST rate in Singapore is 9%. Voluntarily registered businesses must follow the same rules as compulsory ones, like charging GST, filing quarterly, and meeting IRAS requirements.

To register voluntarily, your business must:

Be actively operating in Singapore
Intend to make taxable supplies (now or in the near future)
Be able to comply with GST responsibilities, including record-keeping and return filing
Have a GIRO arrangement in place
Complete the GST e-learning course
Be prepared for a 2-year minimum commitment

When to register for GST voluntarily in Singapore

Even if you’re under the S$1 million mark, voluntary GST registration can pay off, especially if you’re exporting, spending big locally, or scaling fast.

Here’s when it makes sense to register early.

You buy locally but sell overseas
If you export goods or services (which are zero-rated), but spend heavily on local expenses like rent, software, or marketing, GST registration helps you claim input tax.

You want to appear more credible to clients
Having a GST registration number signals professionalism and business maturity, which can be especially useful when dealing with larger organisations or government-linked entities.

You incur high GST-charged expenses
If your business regularly pays GST on operating costs like rent, inventory, or services, voluntary registration allows you to recover that 9%.
You’re scaling fast and will hit S$1M soon
Voluntarily registering before hitting the mandatory threshold gives you time to prepare pricing, systems, and invoicing in advance.

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Pro Tip: To make sure you're prepared, use this GST compliance checklist to review your processes and avoid common mistakes.

Voluntary GST registration vs. Not registering: Quick comparison

Not sure if it’s really worth the effort for your business? Here’s a side-by-side comparison of the key differences to help you decide faster:

Feature / Obligation	Voluntarily Registered Business	Not Registered Business
Can claim input GST	Yes	No
Must charge 9% GST	Yes	No
Quarterly GST filings	Yes	No
InvoiceNow compliance (2025–26)	Required	Not required
Minimum 2-year commitment	Yes	No
Best for B2B	Often	Depends
Best for B2C	Risky	Often
Admin & paperwork	More	Less

Cost-benefit analysis

Wondering how much you can actually save with voluntary GST registration? Well, it can unlock serious cash flow if your business spends enough on GST-inclusive items.

Here’s a simple example:

Monthly expenses: S$8,000
GST rate: 9%
Input tax claim: S$720/month → S$8,640/year

Now subtract the cost of compliance:

Sleek’s GST filing service: S$100/month → S$1,200/year

Net gain:
S$8,640 – S$1,200 = S$7,440/year

That’s over S$14,800 across the 2-year commitment, back into your business, not buried in admin.

This kind of ROI makes voluntary GST registration a smart move for many businesses, especially those with GST-registered clients.

When not to register for GST voluntarily in Singapore

If your business is small, local, or low on expenses, getting GST registered might just add extra admin with little to gain. Here’s when it’s better to hold off.

Your customers are mostly local and price-sensitive
Charging 9% GST can hurt your competitiveness if your clients aren’t GST-registered and can’t claim it back.

You’ve low business expenses with minimal GST paid
If your operating costs don’t include many GST-inclusive items, there’s little input tax to claim.
You’re testing the waters or running short-term operations
Since voluntary GST registration requires a minimum two-year commitment, it may not suit short-term ventures.
You want to avoid added admin and compliance tasks
GST registration involves filing quarterly returns, maintaining detailed records, and potentially adopting InvoiceNow.

Pros and cons of registering voluntarily for GST in Singapore

If you’re still on the fence regarding registering for GST voluntarily, here’s a quick side-by-side look at the upsides and trade-offs to help you decide faster.

Pros and cons of Voluntary GST registration

How to register for GST voluntarily in Singapore

Going in for voluntary GST registration ? Here’s how to do it:

1. Complete the GST e-Learning course

Before IRAS lets you register voluntarily, you’ll need to take their short online course. It covers your responsibilities as a GST-registered business and helps ensure you know what you’re signing up for.

2. Make sure you’ve a GIRO-enabled business account

IRAS requires all voluntarily registered businesses to use GIRO for both GST payments and refunds. If you haven’t already, set up a GIRO arrangement through your corporate bank account.

3. Register for GST via IRAS’ myTax portal

Once you’re ready, head to the myTax Portal and submit your application online under “GST Registration.” Make sure you have your Corppass login ready. You’ll need to upload basic business info and supporting documents.

4. Set up InvoiceNow and maintain proper records

From 1 November 2025, InvoiceNow is mandatory if you’re a newly incorporated company applying for GST. From 1 April 2026, it applies to all new voluntary GST registrants. If that’s you, you’ll need to sign up for InvoiceNow, get a Peppol ID, and use an InvoiceNow-ready system before applying.

Once registered, you’ll send invoice data to IRAS for most sales and purchases. It makes compliance easier, speeds up refunds, and lowers audit risk.

5. Wait for IRAS approval (Usually 10–30 days)

IRAS typically processes voluntary GST registrations within 2–4 weeks. Once approved, your effective date will be stated in your approval letter. Don’t start charging GST before that.

Once you’re in, you’re in. Voluntary registration under GST comes with a minimum two-year commitment, so make sure it aligns with your long-term plans.

How Sleek helps with GST voluntary registration

Voluntary GST registration can feel a little overwhelming at first, especially with all the rules, forms, and deadlines. Sleek helps make the process easier to manage, from start to finish.

Figuring out if it’s right for you: Not sure if registering makes sense? We help you weigh the pros and cons based on how your business runs and what you’re spending.
Getting registered (without the guesswork): From completing the IRAS e-learning to setting up GIRO and InvoiceNow, we guide you through what’s needed so you don’t miss a step.
Handling quarterly filings: Once you’re registered, we help keep your filings on track, accurate, and on time.
Staying compliant: We help you stay on top of your records and GST claims so you’re always audit-ready (just in case IRAS ever asks).
Being there if questions come up: If IRAS needs more info or sends a letter your way, we’re around to help you respond confidently.

Basically, we help take the pressure off while you stay focused on building your brand, closing sales, or just surviving year one in business.

Start your GST journey with clarity.

FAQs on Voluntary GST Registration in Singapore

Can I deregister from GST before the 2-year period ends?

No, businesses that register for GST voluntarily in Singapore must stay registered for at least two years. This is a fixed compliance requirement by IRAS. Even if your business shuts down temporarily, pauses operations, or sees a drop in revenue, early deregistration is not allowed during this mandatory commitment period.

Do I need to file GST returns if I have no sales?

Yes, GST-registered businesses in Singapore must file quarterly GST returns even with no sales. IRAS requires all registered businesses to submit returns, regardless of whether they made any income or taxable supplies during that period. Failing to file can result in late submission penalties or fines, even if you owe nothing.

Will IRAS audit my business after I register?

Not automatically, but voluntary GST registration increases your reporting responsibilities and audit risk. While IRAS does not audit every business, discrepancies in GST filings, unusual refund claims, or a history of late submissions can trigger an audit. Keeping proper tax invoices and documentation is essential.

Can I claim GST on past business expenses?

Yes, you may be allowed to claim input GST on eligible pre-registration expenses made within 6 months before your GST effective date. However, these expenses must be directly related to your business’s taxable supplies. IRAS also requires full documentation, including valid tax invoices, to approve such claims.

Is voluntary GST registration better for B2B or B2C businesses?

Voluntary GST registration usually benefits B2B businesses more than B2C businesses in Singapore. That’s because B2B clients are often GST-registered and can claim back the GST you charge. In contrast, B2C customers cannot recover GST, so charging it may increase your prices and hurt competitiveness.

What happens if I don’t register when I should?

If your taxable turnover exceeds S$1 million and you fail to register for GST, IRAS may backdate your registration and impose penalties. You’ll be liable for GST on past sales, even if you didn’t charge your customers, and you may face fines or interest on overdue amounts.

Can I do my GST filings myself, or do I need an accountant?

You can file GST returns yourself via IRAS’ myTax Portal, but many Singapore businesses use a tax agent or accountant. Filing yourself is possible, especially with simple transactions, but using a GST-registered filing agent helps reduce the risk of errors and ensures timely compliance, especially if you’re claiming input tax or dealing with exports.

What types of invoices need to be sent via InvoiceNow?

Under the GST InvoiceNow Requirement, businesses must send invoice data for standard-rated, zero-rated, and GST exempt supplies, as well as standard-rated and zero-rated purchases. Transactions like reverse charge supplies, import permits, and exempt financial services are excluded from this requirement.