Accounting Solutions Singapore Editorial Team · Last reviewed 18 October 2026. Rules and amounts follow IRAS guidance published in January 2026.
Every GST-registered business files a GST F5 return, usually each quarter, even when nothing happened in the period. The return is short. What takes care is getting each figure into the right box, claiming only the input tax you are entitled to, and filing and paying on time. This page walks through the F5 box by box, then the deadlines, penalties and refunds, and how we prepare it.
At a glance
| Topic | Rule |
|---|---|
| Return | GST F5, filed on the myTax Portal |
| How often | Quarterly, unless you have been approved for monthly filing, which is generally for businesses that expect regular refunds |
| Due date | Filing and payment within one month after the end of the accounting period |
| Nil return | Still required if there was no business in the period |
| Late filing | S$200 immediately, then S$200 for each further completed month, up to S$10,000 per return |
| Late payment | 5% of the tax, plus 2% for each month it stays unpaid beyond 60 days after that, capped at 50% of the outstanding tax |
| Extensions | Generally not granted, and requests must be made before the due date |
| Refunds | Within one month for monthly returns and three months for quarterly returns, after receipt |
The F5, box by box
| Box | What goes in it |
|---|---|
| 1 | Standard-rated supplies, excluding GST. A S$100 sale with S$9 GST puts S$100 in Box 1 |
| 2 | Zero-rated supplies, such as exports of goods and qualifying international services |
| 3 | Exempt supplies, such as residential property sales and leases and certain financial services |
| 4 | Total of Boxes 1, 2 and 3. Calculated automatically |
| 5 | Taxable purchases. Track these separately. IRAS says not to work them out by re-grossing the input tax in Box 7. Imports use the value on the import permit |
| 6 | Output tax due on the Box 1 supplies |
| 7 | Input tax and refunds you are claiming on Box 5 purchases |
| 8 | Net GST: Box 6 minus Box 7, calculated automatically. Amounts under S$5 are not paid or refunded, and are not carried forward |
| 13 | Revenue from the profit and loss account, excluding non-operating income such as disposals of fixed assets and grants |
Example (illustration only). ABC Pte Ltd is registered for GST. In one quarter it makes S$200,000 of standard-rated sales and S$50,000 of zero-rated export sales. It has S$80,000 of taxable purchases with GST of S$7,200, all claimable.
| Box | Amount |
|---|---|
| 1: standard-rated supplies | S$200,000 |
| 2: zero-rated supplies | S$50,000 |
| 3: exempt supplies | S$0 |
| 4: total supplies | S$250,000 |
| 5: taxable purchases | S$80,000 |
| 6: output tax at 9% | S$18,000 |
| 7: input tax | S$7,200 |
| 8: net GST payable | S$10,800 |
Claiming input tax
IRAS lists conditions for claiming input tax. The main ones are that you are GST-registered, the goods or services were supplied to you, you hold a valid tax invoice or import permit in your name, they are used or will be used for your business, the tax relates to taxable supplies, and the claim is not one the regulations block. IRAS also expects you to take reasonable steps to rule out Missing Trader Fraud. Simplified tax invoices are accepted for purchases of S$1,000 or less.
GST on these is not claimable:
- club subscriptions and membership fees
- staff medical expenses and medical or accident insurance, unless certain conditions are met
- benefits for staff family members or relatives
- motor car costs and running expenses, with limited exceptions
- betting, sweepstakes, lotteries and games of chance
- fringe benefits given only to a sole proprietor, partners or directors
Input tax is claimed in the accounting period matching the date of the invoice or import permit. Our post on the conditions for claiming GST input tax goes through them in more detail. A mistake in a past claim is corrected through the process described on our GST services page.
Zero-rated sales need evidence
Exports of goods and international services in section 21(3) of the GST Act are zero-rated. Not every service sold to an overseas customer qualifies. For exports you need to be certain, at the time of supply, that the goods will be or have been exported and that you hold the required documents. IRAS sets those out in its guide on exports and in its page on international services. Zero-rating is where we spend most of our checking time, since a wrong call changes the rate on the whole sale. Our post on when to charge GST goes through the cases.
Filing and paying
- Who files. Only authorised persons can e-file. A business can appoint staff or a third party as a Preparer, who drafts the return, and an Approver, who reviews and submits it to IRAS.
- When. Within one month after the accounting period ends. Payment is due by the same date.
- How to pay. With GIRO, payment is deducted on the 15th of the following month, or the next working day, and IRAS strongly encourages it. Other options include PayNow QR, internet banking, DBS PayLah!, phone banking, ATM, AXS, SAM and NETS at the post office. Overseas companies without a local bank account use telegraphic transfer.
- Extensions. IRAS generally does not grant them. A newly registered business can ask for up to a month on its first return, and a few circumstances, such as a computer breakdown, are accepted. Maternity leave, overseas directors and manpower shortages are not.
Late filing and late payment
A late return carries a S$200 penalty immediately and S$200 for each further completed month, up to S$10,000 per return. IRAS may also issue an estimated assessment with a 5% penalty, and non-filing can lead to a court summons. Late payment carries 5% of the tax, plus 2% a month if it is still unpaid 60 days later, up to 50% of the outstanding tax.
For a return showing S$10,000 of tax, filed and paid 20 days late, that is S$200 for filing and S$500 for payment, S$700 in all.
InvoiceNow and your returns
InvoiceNow does not replace the F5. It sends your invoice data to IRAS alongside it. Which date applies to you depends on how and when you registered. See our pages on the GST InvoiceNow requirement and InvoiceNow set-up.
Refunds
If Box 7 is larger than Box 6, IRAS refunds the difference, within one month for a monthly return and three months for a quarterly return, after receipt. IRAS can withhold a refund for an outstanding return, unpaid tax or penalties, or an audit where information has not been supplied. Refunds go to the business, not to directors or partners.
An accounting scheme worth knowing
The Cash Accounting Scheme lets a GST-registered business with annual sales of up to S$1 million account for output tax when payment is received and input tax when payment is made. IRAS sets conditions for it, so check them before applying.
How we prepare your return
| Step | What we do |
|---|---|
| 1 | Reconcile the GST in your books to your sales and purchase records for the period |
| 2 | Check each zero-rated sale for the evidence IRAS expects |
| 3 | Check each input tax claim for a valid invoice and for anything on the blocked list |
| 4 | Complete the F5, including revenue in Box 13, and send it to you for approval |
| 5 | Submit it on the myTax Portal before the due date, and confirm the payment method |
It works best when the books are kept by the same people who file, so we usually do this alongside your monthly bookkeeping. If a past return needs a review, see our GST audit preparation page. If you are not registered yet, start with our GST registration page.
Questions we get asked
How often do I file? Quarterly, unless IRAS has approved monthly filing for you.
Do I file if I had no sales? Yes. A nil return is still required.
Can I get more time? Rarely. IRAS generally does not grant extensions, and you must ask before the due date.
What if my return shows a refund? IRAS pays it within one month for a monthly return and three months for a quarterly one, subject to the withholding rules above.
Can I claim GST on a company car? IRAS blocks input tax on motor car costs and running expenses, with limited exceptions.
Which accounting period do I claim input tax in? The period matching the date of the invoice or import permit.
What do I put in Box 13? Revenue from your profit and loss account, excluding non-operating income such as asset disposals and grants. IRAS says to use the figure whether or not it has been audited.
Talk to us about your GST returns
Tell us when you registered, how often you file and when you last filed, and we will tell you what is due and what needs checking. Ask us about your GST returns.
Sources
- IRAS, How do I prepare my GST return? (Eleventh Edition, 30 January 2026)
- IRAS, GST: General Guide for Businesses (Seventeenth Edition, 30 January 2026)
- IRAS, GST filing due dates and requests for extension
This page is general information as at the date above, not legal, regulatory or professional advice. Rules and penalties change, so please take advice on your own circumstances before acting.