- A GST-registered business files a GST F5 for each accounting period and pays any tax due within one month of the period ending.
- The F5 has 15 boxes, but the figure that matters most is Box 8, your output tax minus your input tax.
- Most businesses file quarterly through myTax Portal using Corppass, and a nil return is still required when there were no transactions.
- Miss the deadline and IRAS charges S$200 a month up to S$10,000, plus 5% on unpaid tax, and you must keep records for five years.
GST filing in Singapore comes down to one form, the GST F5, and one hard deadline. For each accounting period, a GST-registered business reports the output tax it charged and the input tax it’s reclaiming, then pays or claims back the difference through myTax Portal. Both the return and the payment fall due one month after the period ends, and you file for every period, even a nil one. This guide walks the whole journey, from filling in each box to hitting submit, and shows where expert GST filing help fits if you’d rather not do it alone.
Staring at your first F5 with the deadline days away, unsure which figure belongs in which box?
What is GST filing, and when is your return due?
GST filing is how a GST-registered business reports the tax it charged customers and the tax it paid suppliers, over a fixed stretch of time called an accounting period. You report it on a single form, the GST F5 return, and submit it online through IRAS’s myTax Portal. The return and any payment are both due one month after the accounting period ends.
The current GST rate is 9%. You charge that on your standard-rated sales, which is your output tax, and you can usually claim back the 9% you paid on business purchases, which is your input tax. You file on time for every period, even when there’s nothing to report.
Just need your next date? Skip to the filing calendar below.
Who has to file a GST return, and how often?
You file for GST once your business is GST-registered. Registration is compulsory when your taxable turnover passes S$1 million over a 12-month period, and optional below that through voluntary registration. Registration comes first, and filing is the ongoing obligation that follows it.
IRAS assigns each business an accounting period, and for most that’s quarterly, so four returns a year. Some businesses file monthly, usually because they claim regular refunds and want them back sooner. Whatever your cycle, the one-month deadline after each period end is the same.
What goes in each box of the GST F5 return?
The F5 has 15 boxes, but most small businesses only touch a handful of them. Here’s what each box captures, so you can see which ones actually apply to you.
| Box | What it captures |
|---|---|
| Box 1 | Total value of standard-rated supplies (your sales taxed at 9%, excluding the GST itself) |
| Box 2 | Total value of zero-rated supplies (exports and qualifying international services) |
| Box 3 | Total value of exempt supplies (residential property, most financial services, investment precious metals) |
| Box 4 | Total of Boxes 1, 2 and 3 |
| Box 5 | Total value of taxable purchases (standard-rated purchases from your suppliers’ tax invoices) |
| Box 6 | Output tax due (GST you charged on Box 1 supplies, plus certain adjustments) |
| Box 7 | Input tax and refunds claimed (GST on your purchases, plus tourist and bad-debt reliefs) |
| Box 8 | Net GST: Box 6 minus Box 7 (what you pay IRAS, or reclaim) |
| Box 9 | Value of goods imported under MES, Approved 3PL or other approved schemes |
| Box 10 | Whether you claimed GST that was refunded to tourists |
| Box 11 | Whether you made bad-debt or reverse-charge refund claims |
| Box 12 | Whether you made pre-registration claims (first return only) |
| Box 13 | Revenue (your main business income from your profit and loss account) |
| Box 14 | Whether you imported services under reverse charge |
| Box 15 | Whether you operated an electronic marketplace |
Boxes 1 to 4 are your sales, split by how they’re taxed. If some of your sales are zero-rated, they go in Box 2, and exempt supplies go in Box 3. Boxes 6, 7 and 8 are where the tax itself is worked out.
Output tax, input tax, and working out what you owe
Output tax is the GST you collect on your sales. Input tax is the GST you pay on business purchases and can claim back. The gap between the two is the whole point of the return.
If your output tax in Box 6 is higher than your input tax in Box 7, you pay the difference to IRAS. If your input tax is higher, IRAS refunds you. Either way, that single figure lands in Box 8.
Here’s a quick worked example. Say you charged 9% GST on S$100,000 of sales, that’s S$9,000 of output tax, and you paid 9% on S$40,000 of purchases, that’s S$3,600 of input tax. Box 8 would show S$5,400 payable to IRAS.
How do you find your next GST filing deadline?
The rule is short: your GST F5 and any payment are due one month after your accounting period ends. Work from your own period end and you won’t be caught out. Your GST submission deadline is the single date worth putting in your calendar, because missing it is what starts the penalties.
| Accounting period | Period ends | Return and payment due |
|---|---|---|
| Jan to Mar | 31 March | 30 April |
| Apr to Jun | 30 June | 31 July |
| Jul to Sep | 30 September | 31 October |
| Oct to Dec | 31 December | 31 January |
Those dates assume the standard quarterly cycle. If IRAS has placed you on monthly filing or a different set of quarters, apply the same one-month rule to your own period end. Paying by GIRO helps, since the deduction is taken automatically and the payment side of the GST submission deadline looks after itself.
TIPTip. Set your reminder for a week before each due date, not the day itself. Reconciling your accounts and clearing any odd transactions usually takes longer than the filing does.
How do you submit your GST return on myTax Portal?
All GST returns are filed electronically through myTax Portal. There’s no paper form and no email option. You log in, open the GST F5 for the current period, fill in the boxes, review the figures, and submit.
Those figures should come straight from your accounting records, so the portal step is mostly checking and confirming rather than calculating. Once you submit, you get an acknowledgement, and payment follows by the same deadline. The e-filing of GST return is fast when your books are already reconciled, and slow when they aren’t.
Gst filing login: what access do you need before you start?
The gst filing login that trips people up isn’t a separate GST password. You reach the F5 by logging in to myTax Portal with Corppass, Singapore’s business login, and whoever files must be authorised for GST on the company’s Corppass account.
If you can’t see the GST F5 after you log in, it’s almost always an access problem, not a portal fault. Your Corppass administrator needs to grant you the GST filing role first. Sort that out before deadline week, because the e-filing of GST return can stall for a day or two while approvals come through.
Can you file GST when your books are in Xero?
For most businesses, yes, and it’s the practical route. Xero and similar software track GST on every invoice and bill, then produce a GST return that maps to the F5 boxes, so you’re transcribing far less by hand.
The catch is that software is only as accurate as the tax codes behind it. A sale marked zero-rated that should be standard-rated, or a blocked expense claimed as input tax, flows straight into your return. A human review before you submit is what catches those, which is where outsourced accounting and tax support earns its keep.
Can I file my GST return myself?
For a simple business, the answer is yes. If you sell standard-rated goods or services in Singapore, keep clean records in accounting software, and have no unusual transactions, filing your own F5 is well within reach. The question “can I file GST return myself” comes up constantly, and the honest answer turns on how complex your GST position is, not on how clever you are.
It stops being a do-it-yourself job in a few situations, and each is a place where a wrong figure is expensive to unwind.
| Your situation | File it yourself? | What makes it tricky | Cost of getting it wrong |
|---|---|---|---|
| Simple standard-rated business, clean books | Usually yes | Little beyond accurate bookkeeping | Low, and easy to correct |
| Mix of exempt and taxable supplies | Often not | Input tax must be apportioned, so only part is claimable | Over-claimed input tax, repayable with penalties |
| Exporter relying on zero-rating | Care needed | Zero-rating needs supporting export evidence | Zero-rated sales reclassified at 9%, tax plus penalty |
| Buying imported services or goods | Care needed | Reverse charge may apply, so you account for the GST yourself | Missed output tax, flagged on audit |
| Behind on past filings | Get help | Catch-up returns and F7 corrections stack up | S$200 a month per return, up to S$10,000 |
So, can I file GST return myself and stay compliant? For a simple business, comfortably. If you recognise your company in the lower rows, the time you save can be wiped out by a single correction, and that’s the real trade to weigh.
What does GST filing cost, doing it yourself versus outsourcing?
Filing it yourself costs nothing in fees. IRAS doesn’t charge to submit a GST return, so the only real cost is your time and the risk of an error. For a simple quarterly return with tidy books, that’s often an hour or two each quarter.
Outsourcing trades that time for a fixed fee. As a guide, Sleek’s standalone GST filing starts from S$100 a month, or S$300 a quarter, covering preparation, an accuracy review, and submission to IRAS. Promotions move these figures, so check the current price on the service page before you decide.
The maths is simple enough. If your GST is straightforward, doing it yourself is fine. If one error would cost you more than the fee, or you’d simply rather not track the deadline, outsourcing pays for itself.
What happens if you file late, or file it wrong?
Miss the deadline and IRAS charges a late submission penalty of S$200 the moment the return is overdue, then a further S$200 for every completed month it stays outstanding, up to S$10,000 per return. That penalty applies before any tax is even counted, which is why an on-time nil return still matters.
Late payment is a separate charge. IRAS adds a 5% penalty on the unpaid tax, and if it’s still unpaid 60 days after the due date, a further 2% for each month it remains outstanding, up to a maximum of 50% of the tax owed. If you file for GST late and then ignore the demand, IRAS can raise an estimated assessment or take recovery action, and common filing errors are worth reading before your first return so you don’t land here.
Made an honest mistake on a return you’ve already filed? You correct it with a GST F7, not by editing the original F5. If you’re winding the business down instead, that’s a different form and a different process, and the GST deregistration guide covers that route.
What records do you have to keep, and for how long?
You must keep your GST records for at least five years, even after the return is filed and settled. That covers your tax invoices, receipts, import and export documents, and the accounting records behind each figure you reported.
The reason is audit. IRAS can review past returns, and that five-year trail is how you back up the numbers you filed. Accounting software helps here too, because a clean digital record is far easier to produce than a drawer full of receipts.
How Sleek helps you stay on top of GST filing
GST filing rewards two things, accurate books and a deadline you never miss, and both are easy to let slip when you’re running everything else. Sleek prepares your F5 from your accounting records, reviews the input and output tax, and submits it to IRAS ahead of each deadline, nil returns included. If you’d rather hand the whole cycle over, from bookkeeping to submission, that’s exactly what the service is built to do.
Stop watching the GST calendar and let a specialist file for you.
Sleek preps, reviews, and submits your GST returns on time, every period.
Prices may vary with current promotions. Check the latest on the relevant page.
450,000
businesses worldwide.
from 4,100+ reviews.
FAQs on gst filing
Does IRAS charge a fee to file a GST return?
No. IRAS doesn’t charge anything to submit the GST F5 through myTax Portal, so filing itself is free. The only cost is your time, or a provider’s fee if you outsource. Charges only appear when you’re late, at S$200 for each month a return is overdue.
Do I still file a GST return if my business had no transactions?
Yes. A return is required for every accounting period, even with nothing to report, which is called a nil return. You file the F5 with zeros in the relevant boxes. Skipping it still counts as late filing and still attracts the S$200 monthly penalty.
How do I correct a mistake on a GST return I've already filed?
You file a separate GST F7 return to correct errors in a return you’ve already submitted, rather than changing the original F5. Disclose it as soon as you spot it, because a voluntary correction is treated far more favourably than an error IRAS finds first. Smaller errors within IRAS’s set limits can sometimes be adjusted in your next F5 instead.
Do I still file a return if I'm expecting a GST refund?
Yes. When your input tax is higher than your output tax, you still file the F5 as usual, and Box 8 simply shows a refund due to you rather than tax payable. IRAS processes the refund after the return is filed, so filing on time is what starts that clock.
What's the difference between the GST F5 and the F8 return?
The F5 is your regular return for each accounting period. The F8 is the final GST return you file when you cancel your GST registration, covering the last stretch up to your deregistration date. Most businesses only ever deal with the F5.
Do I need to be GST-registered before I can file?
Yes. Filing follows registration, and you only file GST returns once your business is registered. Registration is compulsory when your taxable turnover crosses S$1 million over 12 months, and voluntary below that. Until you’re registered, there’s no F5 to file.
Can I get more time to file my GST return?
IRAS expects the F5 by the one-month deadline and doesn’t grant extensions as a matter of routine. If a genuine problem means you can’t file in time, contact IRAS before the due date rather than after. Filing late without an arrangement triggers the S$200 monthly penalty straight away.
