A Guide for Small Businesses on How to Register and File GST in Singapore

The Goods and Services Tax (GST) system can be hard to understand for small and medium-sized businesses (SMEs) in Singapore [1], [2].

It’s important to know how the process works, whether you’re close to the mandatory registration threshold or registering voluntarily to make your business look more credible. This guide tells you everything you need to know about registering for GST and filing your taxes in Singapore, from figuring out how much you owe to filing your F5 return correctly [3].

When do you need to register for GST? Knowing the Threshold

“Do I need to register for GST?” is the first thing every business owner asks [1].

If you live in Singapore, you must register for GST if [2]:

At the end of any calendar year, your taxable turnover is more than $1 million.
You have good reasons to think that your sales will go over $1 million in the next year.

But even if your sales are below the limit, businesses that choose to register for GST may still benefit from it [4]:

Deal mostly with customers who are registered for GST and can claim input tax.
Want to get input tax back on things they buy for their own business.
Want to improve how people see their business.

Pro Tip: If most of your customers are regular people or businesses that don’t have a GST number, registering voluntarily could make your prices less competitive because you’ll have to charge 9% GST on your supplies [3].

The Step-by-Step Process for Registering for GST

It’s easy to sign up for GST with IRAS, but you need to be accurate [5]. This is what you need to do:

1. Get your papers ready Before you start your application, get:

ACRA business profile (updated in the last six months)
Financial forecasts (for optional registration)
Information about what your business does and what supplies it needs

2. Send in your application Use your CorpPass to log in to myTax Portal and fill out the GST registration form (GST F1). For local businesses, the process usually takes 10 business days [5].

3. Get Your Letter of Approval After you get the go-ahead, IRAS will give you your GST registration number and the date it goes into effect. You’ll also get the dates when your taxes are due and a confirmation of your accounting period [1].

4. Get your systems ready Before your effective date, make sure your accounting software is ready for GST, update your invoices to include all the necessary information, and teach your employees how to properly issue tax invoices [6].

Understanding GST Accounting: What Every Small Business Should Know

Knowing how to properly account for GST stops you from making expensive mistakes when you file [3].

Output Tax and Input Tax

Output Tax: GST you add to the price of your goods (supplies). You get this from customers. Must be paid to IRAS.
Input Tax: GST you pay when you buy things for your business. You give this money to suppliers. Can be claimed back from IRAS.

Supplies that are standard-rated, zero-rated, or exempt Not all supplies are treated the same [2]:

Standard-Rated (9%): Most local sales of goods and services
Zero-Rated (0%): Exports and international services (you can still claim input tax)
Not subject to GST: Financial services and sales of residential property (no GST charged and no input tax claimable on related costs)

Deadlines and cycles for filing GST

Most companies file their GST returns every three months [4]. Your business type and election will determine your accounting period:

Filing every three months is normal for most businesses.
Monthly filing: For businesses that need a lot of money back or have special needs.
Half-yearly filing: Only some businesses can do this with permission.

You have until the last day of the month after your accounting period ends to file your F5 return and pay any taxes you owe [1].

What Happens If You File After the Deadline?

IRAS gives out penalties [7]:

Filing late: $200 fine for each return
If you don’t pay your taxes on time, you’ll have to pay 5% more, plus 2% more for every month after that (up to 50%)

Common GST Claims and Mistakes That Cost You Money

What You Can Claim (Valid Input Tax) You can get input tax back on things you buy for your business if [2]:

You have a real tax invoice
The goods and services are for business use
You make taxable supplies, either at the standard rate or at the zero rate

Things That Often Lead to IRAS Audits [3], [7]:

Claiming input tax on blocked claims, like medical bills, luxury cars, and benefits for family members
Incorrect tax invoices—fields that need to be filled out are missing
Claiming at the wrong time—claiming in the wrong accounting period
Not paying attention to reverse charge—this applies to businesses that import services and have more than $1 million in relevant supplies
Not keeping track of changes in use—when business assets are used for personal reasons

Warning: IRAS audits people on a regular basis and can give them big fines for making false claims, even if they were honest mistakes [7].

A List of Things to Check on a GST Invoice

Every tax invoice you send or receive must include the following to make sure your claims are valid [2], [6]:

☑️ “Tax Invoice” heading

☑️ Your business name, address, and GST registration number

☑️ Name and address of the customer

☑️ Date of invoice and unique invoice number

☑️ A description of the goods or services provided

☑️ Quantity or volume of goods provided

☑️ Total amount due without GST

☑️ GST rate (9%) and total GST due

☑️ Total amount due with GST

When you send a simplified tax invoice (for amounts under $1,000), you don’t need to include as much information, but you still need to include the supplier’s name, GST registration number, invoice date, and total amount including GST [6].

Tips for SMEs on GST Software

Picking the right accounting and bookkeeping services and software makes it a lot easier to follow the rules [8]. Look for things like:

Automatic calculation of GST on transactions
Your entries will fill out the F5 return for you
Templates for tax invoices that meet IRAS standards
GST audit trail for simple review
Cloud access lets you work with your bookkeeper in real time

How Professional GST Filing Services Can Help

There are many benefits to having experts like PC Lee & Co handle the paperwork and file your GST for you [9]:

Avoiding mistakes: Professionals find possible problems before they are sent in.
Time savings: Let us take care of compliance so you can run your business.
Strategic advice: Make the most of your GST situation and plan for growth.
Audit help: If IRAS questions your return, you can rest easy knowing that an expert is there to help.

We keep up with the most recent IRAS rules and can help with anything from signing up to voluntarily admitting to past mistakes [9].

Your GST Filing Checklist: Ready for the End of the Quarter

Before you send in your next F5, use this easy checklist [3], [7]:

✅ Make sure all sales and purchase records match up

✅ Check that all tax invoices are complete and correct

✅ Keep personal and business costs separate

✅ Check claims that have been blocked and make sure that no wrong input tax has been claimed

✅ Check the exchange rates for transactions with other countries

✅ Check that the numbers on your F5 match those in your accounting records

✅ Submit by the due date and pay any taxes owed

Want to make your GST compliance easier?

Filing your GST doesn’t have to be hard. Professional help makes all the difference, whether you’re getting close to the registration threshold, getting ready for your first return, or trying to make your current process easier [9].

At PC Lee & Co, we help small and medium-sized businesses confidently deal with Singapore’s tax system. Our team will make sure you stay compliant while you focus on what you do best: growing your business. We handle everything from registering for GST to filing quarterly and giving you strategic advice.

Get in touch with us today to set up a consultation and find out how our GST filing services in Singapore can make compliance easier. You work on your future while we take care of the numbers.

📞 Call us at 6737 3710

✉️ Email: enquiries@pc-lee.com

📍 Visit: 545 Orchard Road, #10-06 Far East Shopping Centre, Singapore 238882