- Once you register, GST becomes an ongoing cycle: charge 9%, invoice correctly, file, pay, and keep records for five years.
- Your GST F5 return and payment are both due 1 month after the end of each accounting period, typically quarterly.
- Late filing costs S$200 per month, up to S$10,000 per return; late payment adds 5% plus 2% per month, up to 50% of the tax owed.
A GST compliance checklist for businesses turns a pile of IRAS obligations into a short list you can actually work through. Once your company crosses the S$1 million turnover mark and registers, GST stops being a one-off task and becomes an ongoing rhythm that a GST filing service can run for you, or that you manage yourself. Charge the right rate, invoice correctly, file on time, pay on time, keep clean records. Miss a step, and the penalties are fixed and automatic, not up for negotiation. This guide sets out every obligation in the order it reaches you, with the deadline and the cost of getting it wrong beside each one.
Registered for GST and quietly unsure what you now owe IRAS, and by when?
What do you have to do once you’re GST-registered?
Once you’re registered, you have to charge 9% GST on your standard-rated sales, issue proper tax invoices, file a GST F5 return and pay what you owe one month after each accounting period, claim only the input tax you’re allowed, and keep every supporting record for five years. That is the whole of GST compliance in Singapore in one sentence. The rest of this page is that sentence broken into dated, checkable steps.
Here is the complete list. Work down it in order, and treat the final column as the reason each row matters.
| Obligation | Frequency | Deadline | If you miss it |
|---|---|---|---|
| Monitor turnover against the S$1 million threshold | Ongoing | Retrospective test: at each calendar year end. Prospective test: the day you reasonably expect to cross it | Backdated registration, a fine of up to S$10,000, and a 10% penalty on the GST due |
| Apply to register once you’re liable | Once | Within 30 days of becoming liable; IRAS takes up to ten working days to process | As above |
| Charge GST at 9% from your effective date | Every sale | From the effective date shown on your registration notice | You still owe the 9% to IRAS even if you never collected it from the customer |
| Issue compliant tax invoices | Every standard-rated sale | At the point of sale, and keep a copy | Customers can’t claim their input tax, and your records fail an IRAS review |
| File your GST F5 return | Quarterly (monthly by application) | One month after the end of each accounting period | S$200 the day it’s late, plus S$200 for each further completed month, up to S$10,000 per return |
| Pay the GST due | Same cycle as filing | One month after the end of the accounting period | A 5% penalty, then an extra 2% a month once you’re 60 days late, up to 50% of the tax owed |
| Claim only allowable input tax | Each return | Within the return for that period | Wrongful claims are recovered with penalties; blocked expenses stay blocked |
| Keep full GST records | Ongoing | Retain for five years (electronic is fine) | Records you can’t produce leave you open to assessment and penalties |
| Report changes and deregister when eligible | As they arise | Notify IRAS within 30 days of the change | Charging GST after you should have deregistered creates fresh liabilities |
All figures are from IRAS, as at August 2026. Keep this table where whoever raises your invoices can see it, because most of these rows are someone’s daily habit rather than a once-a-year event.
When does GST registration actually bite?
Registration is triggered two ways, and a complete GST registration checklist has to cover both. The retrospective test looks back: at the end of each calendar year, if your taxable turnover for that year passed S$1 million, you must register. The prospective test looks forward: the day you can reasonably forecast the next 12 months will exceed S$1 million, the clock starts.
You then have 30 days to apply through myTax Portal, and IRAS takes up to ten working days to process it. Your effective date is set for you, so you can be liable to charge GST before your GST number arrives. Use the GST registration service or apply yourself, but do not wait for the paperwork to catch up. If you need to confirm a supplier’s status in the meantime, you can check a business’s GST registration directly.
How do you charge GST correctly at 9%?
From your effective date, charge 9% on standard-rated supplies, which is most local sales of goods and services. Exports and certain international services are zero-rated, and a short list of financial services and residential property is exempt, so those carry no GST. Getting the category right is where GST compliance in Singapore usually goes wrong, and the complete guide to GST in Singapore sets out the boundaries in detail.
What has to appear on a tax invoice?
For any standard-rated sale above S$1,000, you must issue a full tax invoice. IRAS requires it to show the words “tax invoice”, your business name, address and GST registration number, an invoice number and date, your customer’s name and address, a description of what was supplied, the amount before GST, the GST rate and amount shown separately, and the total payable. For sales of S$1,000 or less, a simplified tax invoice is enough, showing your details, the date, a description, and the total with a note that it includes GST.
How do you file and pay GST on time?
Most businesses file a GST F5 return every quarter, aligned to their financial year end, though you can apply to file monthly if you’re regularly in a refund position. Both the return and the payment are due one month after the end of the accounting period. The mechanics of completing the form are covered in how to file your GST return, so this section is only about the obligation and the clock.
Two separate penalties apply, and they stack. File late and IRAS imposes S$200 straight away, then a further S$200 for every completed month the return stays outstanding, up to S$10,000 per return. Pay late, and you’re charged 5% of the tax due, then an additional 2% for each month it remains unpaid once you’re past 60 days, up to a maximum of 50% of the outstanding tax.
TIPWhat GST can you claim back, and what’s blocked?
You can claim input tax on GST you paid on business purchases, which is what makes registration worth it. To claim, you must be registered, hold a valid tax invoice, use the purchase for your business, and be making taxable supplies with it. Getting this right is the heart of Singapore GST expense compliance, and it’s where a tidy expense process pays for itself.
Some expenses are blocked no matter how business-related they feel. Under IRAS Regulations 26 and 27, you can’t claim input tax on the cost and running of private motor cars, club subscription and membership fees, medical expenses and medical or accident insurance (unless the law or a collective agreement requires them), benefits given to your staff’s family members, and anything to do with betting or games of chance. Claiming on these is one of the most common review findings, so keep them out of your input tax total.
How long do you keep GST records?
Five years. Under the GST Act, a GST-registered business must keep its tax invoices, receipts, accounting records, and business documents for at least five years, and companies keep them for a further five years after striking off. You may hold everything electronically without asking IRAS for approval, as long as your system keeps the records complete, accurate, and readable. Good accounting software makes this the easy part rather than the scramble it becomes at audit.
What must you report, and when can you deregister?
Tell IRAS within 30 days if your business details change, if you stop making taxable supplies, or if you cease trading. If your turnover falls below the threshold and you no longer expect to cross it, you can apply to cancel your registration; the steps are in the guide to deregistering for GST. One item on the horizon belongs here too: e-invoicing rules are tightening, so if you’re adopting InvoiceNow and e-invoicing, fold it into your process now rather than later.
What if you’ve already got something wrong?
Find an error before IRAS does and disclose it. IRAS runs a Voluntary Disclosure Programme, and a timely, self-initiated correction usually means reduced or waived penalties rather than the full amount. Small errors can often be adjusted in your next return; larger ones need a separate correction. The point is simple: a mistake you report is a much cheaper mistake than one that surfaces in a review.
Who actually does this, you, your bookkeeper, or your accountant?
Sales-call transcripts show this is the question founders really want answered: “would the accounting be, like, done on our side?” The honest answer is that GST compliance is mostly a bookkeeping discipline, not a tax puzzle. Businesses that record every sale and expense cleanly, with the invoice attached, rarely have GST problems. The ones that struggle are almost always behind on their books, not confused about the rules.
That’s the real split of work. Someone charges and invoices correctly at the point of sale, someone keeps the records straight through the quarter, and someone prepares and files the return. You can run all three yourself, hand the last one to an accountant, or pass the whole cycle to a provider. Sleek offers accounting services that keep the records and the filing under one roof.
How Sleek helps you stay GST-compliant
Sleek’s GST compliance services cover the recurring cycle end to end: correct invoicing, input tax you’re actually allowed to claim, and the GST F5 filed and paid on time, every quarter. It’s the same work your business already has to do, run by people who do it daily and rated 4.8 out of 5 by more than 4,100 customers. GST filing starts from S$300 a year.
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FAQs on gst compliance checklist for businesses
What is GST compliance?
GST compliance is meeting all the ongoing duties that come with being GST-registered in Singapore: charging the correct rate, issuing valid tax invoices, filing your GST F5 return, paying on time, claiming only allowable input tax, and keeping records for five years. It is a continuing obligation, not a one-time registration step.
What is on the GST registration checklist?
To register, you generally need your ACRA business details, your financial records showing you have crossed or will cross the S$1 million turnover threshold, your business activity details, and, for voluntary registration, a GIRO application. You apply through myTax Portal, and IRAS takes up to ten working days to process it.
What are GST compliance services?
GST compliance services are professional support that handles the recurring GST cycle for you, typically covering invoicing checks, input tax review, and quarterly GST F5 preparation and filing. Providers like Sleek run this as a subscription so the work happens on schedule rather than in a last-minute rush.
Do I need special software to stay GST-compliant?
No specific software is legally required, but accounting software that records transactions and stores tax invoices makes five-year record-keeping and quarterly filing far easier. Separately, keep an eye on Singapore’s e-invoicing rollout through InvoiceNow, which is becoming part of how GST-registered businesses transmit invoice data.
Can my accountant file GST on my behalf?
Yes. You can authorise a tax agent or accountant through Corppass to access myTax Portal and file your GST F5 for you. You remain legally responsible for the accuracy of the return and for paying on time, so the deadlines still sit with your business even when someone else does the filing.
When can I deregister for GST?
You can apply to cancel your GST registration if your taxable turnover has fallen below S$1 million and you don’t expect it to rise above that again, or if you stop making taxable supplies or cease trading. You must apply within 30 days of becoming eligible or required to cancel, and you keep filing and paying until IRAS confirms the cancellation.
If I register for GST voluntarily, do the same compliance rules apply?
Yes, and there’s an extra condition. Voluntary registrants carry exactly the same charging, filing, payment, and record-keeping duties, and they usually must stay registered for at least two years and pay by GIRO. Voluntary registration only makes sense if the input tax you recover outweighs the admin of full compliance.
