When to Register for GST in Singapore: A Business Guide

Had a great year? Fantastic. But that recent success might come with a new task you didn't expect: GST registration.

When do you need to register? What happens if you miss the deadline? There are a lot of questions around GST. Getting it wrong can lead to serious fines.

GST isn't just a compliance headache; it's a major milestone for a growing business. But you have to know the basics. This guide breaks down exactly when you need to register, what it means for your business, so you can handle it without stress.

‍

When Do I Have to Register for GST?

You must register for GST if your business's annual taxable turnover crosses the S$1 million threshold.

There are actually two different triggers: one that looks at the past and one that looks to the future. The Inland Revenue Authority of Singapore (IRAS) wants to know if you've already crossed the line or if you're about to.

‍

Looking Back: The Retrospective View

This is the most straightforward trigger. Add up your total sales for the past calendar year (from January 1st to December 31st).

If your taxable turnover at the end of the calendar year was over S$1 million, you must register for GST.

It’s a simple look at what has already happened. Did your sales for the prior year top S$1 million? If yes, you must register beginning January 1st.

‍

Looking Forward: The Prospective View

You don't have to wait to hit the S$1 million mark to become liable. You must also look ahead to see what’s coming up in your business.

You must register if, at any point, you are certain your taxable turnover will exceed S$1 million in the next 12 months.

This isn't guesswork. This trigger is usually pulled by a specific event. For example, you might have just signed a massive new contract, or your sales are growing so fast that you can clearly project you’ll cross the S$1 million mark within a year.

Here’s a quick scenario:

It's May, and your business has already made SGD700,000 in sales this year. You just landed a new client, and the contract guarantees another S400,000 in revenue over the next six months.

Your projected turnover is now S$1.1 million. Because you can reasonably expect to cross the threshold, you need to register now, not at the end of the year.

‍

What Counts Towards the $1 Million?

This is a key detail that business owners may overlook.

Your "taxable turnover" isn't just your total revenue. It’s the total value of all taxable goods and services you supply in Singapore.

This includes:

• Standard-Rated Supplies: These are most of the goods and services you sell, which will be subject to the standard GST rate (currently 9% in 2025).
• Zero-Rated Supplies: This primarily covers exports and international services. Even though you charge 0% GST on these sales, the revenue still counts towards your S$1 million registration threshold.

What's left out? The calculation excludes a few things:

• Exempt supplies (like providing financial services or leasing residential property).
• The sale of capital assets.
• Revenue from sales made outside of Singapore.
• The GST amount itself.

Getting this calculation right is crucial. If you classify your revenue streams incorrectly, you might register too late or, in some cases, too early.

‍

What Happens If I'm Late to Register?

IRAS is strict about deadlines. Once your business becomes liable for GST registration, either by looking back or looking forward; you have 30 days to submit your application.

Miss that 30-day window, and there could face some painful consequences:

• Late Registration Penalties: IRAS can fine you for failing to register on time.
• Back-Dated GST: A big one. You will be held liable for the GST you should have collected from the date you were required to register. It doesn't matter if you never actually charged your customers for it; you still owe that money to IRAS.
• Interest on Top: You'll also be charged interest on the back-dated GST you owe.

These penalties can create a serious cash flow problem for a small business. That is why keeping an eye on your turnover is so important.

‍

Can I Register Even If I Don't Have To?

Yes, you can. This is called Voluntary GST Registration.

Voluntary GST registration can be a smart move for some businesses, even if their turnover is well below S$1 million.

Why would anyone volunteer to charge their customers more and deal with tax paperwork?

The main reason is to claim back the GST you pay on your business expenses. This is known as claiming "input tax."

If you're a business that spends a lot on GST-registered suppliers, such as inventory, software, rent, or professional services, registering allows you to claim the GST back from the government.

‍

What's the Catch?

Voluntary registration isn't a light decision. If you choose to register, you have to follow all the rules:

• You must charge and account for GST on all your sales, just like a compulsorily registered business.
• You must remain registered for at least two years. You can't just sign up to claim GST on a big purchase and then quickly deregister.
• You (or a director) must complete mandatory e-learning courses on GST provided by IRAS. They want to make sure you know what you're signing up for.

Is it right for you?

If your customers are mainly other GST-registered businesses, they can claim back the GST you charge them, so it won’t affect their bottom line. However, if you primarily sell to the general public (B2C), adding 9% to your prices might make you less competitive. It’s a strategic decision that depends on your business model.

More reading: Bookkeeping for Singapore SMEs: A No-Fuss Guide

‍

What If My Sales Spike Was a One-Off?

What if you sell a major company asset and your revenue temporarily spikes above S$1 million, but you know it won't happen again? Do you still have to register?

Not necessarily.

If you can prove to IRAS that the increase was a one-time event and your turnover will not exceed S$1 million in the next 12 months, you can apply for an exemption from registration. You must formally apply for the exemption and provide strong evidence to support your case.

‍

How Harvest Accounting Can Help

Trying to figure all this out while running your business can feel like a juggling act. You’re focused on growth, clients, and operations, not pouring over tax regulations. That's where we come in.

At Harvest Accounting, we see our role as more than just balancing the books; we act as your growth partners, helping you navigate these milestones with confidence.

• No More Guesswork: We help to keep your books up to date, and we help to monitor your revenue continuously. You won't have to worry about accidentally crossing the GST threshold—we'll alert you well in advance so you can prepare. We help you forecast your turnover, so you’re never caught by surprise.
• Hassle-Free Registration: If you need to register, we handle the entire application process with IRAS. We make sure everything is filed correctly and on time, saving you from the stress of paperwork and the risk of penalties.
• Ongoing Compliance, Sorted: Once you're registered, the real work begins. We manage your quarterly GST filings, ensuring your input and output taxes are reported accurately. We’ll get you set up on modern accounting software like Xero, making record-keeping seamless.
• Strategic Advice: Is voluntary registration right for you? Do you qualify for an exemption? We provide clear, straightforward advice tailored to your specific situation. Harvest together, we can make the right call for your business's future.

[Coming Soon: How Can Singapore Small Businesses Choose The Right Accounting Partner?]

‍

Don't Let GST Be a Hurdle to Growth

Managing your GST obligations is a sign that your business is succeeding. It shouldn't be a source of anxiety. The key is to understand the triggers, respect the deadlines, and know when to ask for help.

By understanding the basics of this article, you can ensure your business stays compliant and financially healthy, leaving you free to focus on the exciting road ahead.

Struggling to keep your books in order? Let our expert team at Harvest Accounting handle the complexities. Contact us today for a consultation and get your GST questions answered.