Every Singapore company must file an annual corporate tax return with IRAS, whether or not the company made a profit. Beyond the filing itself, the real value in proper tax handling is in what gets checked along the way, rebates you’re actually entitled to, deductions that get missed under time pressure, and a computation that holds up if IRAS ever queries it.
What Corporate Tax Filing Actually Involves
Estimated Chargeable Income (ECI)
Most companies must file an ECI within three months of their financial year end, giving IRAS an early estimate of taxable income. Some companies qualify for ECI filing exemption based on revenue and income thresholds, worth confirming your eligibility each year rather than assuming last year’s status still applies.
Form C-S / Form C Filing
The annual tax return itself, filed as either Form C-S (a simplified filing for qualifying smaller companies) or the full Form C, due by the annual filing deadline. Which form applies depends on your company’s revenue and complexity.
Tax Computation
This is where the real work happens, converting your accounting profit into chargeable income by adjusting for non-deductible expenses, capital allowances, and available reliefs. A computation done carelessly either overstates tax payable (missing deductions you’re entitled to) or understates it (creating exposure if queried).
Claiming Rebates and Reliefs
Each year’s Budget can introduce or adjust rebates, for instance, Budget 2026’s 40% Corporate Income Tax rebate, capped at $30,000, applied automatically to qualifying companies. Checking every year’s specific rebates and reliefs against your computation, rather than applying a generic template, is what actually captures the tax benefit you’re entitled to.
GST
Your company must register for GST when its taxable turnover goes over S$1 million. IRAS looks at this in two ways:
- Looking back: if your taxable turnover for the calendar year (January to December) was more than S$1 million, you have 30 days from the end of that year to register.
- Looking ahead: if you can reasonably expect your taxable turnover over the next 12 months to be more than S$1 million, for example because you’ve just signed a large contract, you need to register within 30 days of knowing that.
The second test is the one growing businesses tend to miss. Because we keep your books every month, we can see when you’re getting close and talk to you about it early. Once registered, most businesses file a GST return every quarter, due one month after the end of each quarter.
Withholding Tax and Certificate of Residence
Payments to non-resident companies or individuals for certain types of income (services, royalties, interest) may attract withholding tax, which needs to be correctly identified and remitted. Where a tax treaty applies, obtaining a Certificate of Residence can reduce or eliminate withholding tax but this requires proper documentation and timing to claim.
Personal Tax for Directors and Shareholders
Directors’ fees, salaries, and benefits-in-kind all affect personal tax obligations separately from the company’s own filing worth coordinating rather than treating personal and corporate tax as entirely separate conversations, particularly for owner-directors whose personal and company finances interact closely.
Why the Computation Matters More Than the Filing Itself
The actual ACRA/IRAS filing mechanics are fairly standardized. What varies, and what actually affects how much tax you pay, is the quality of the computation behind it: whether capital allowances were correctly claimed, whether available reliefs were checked against your specific situation, and whether the classification of expenses was done carefully rather than defaulted to whatever categorization was fastest.
Who This Is For
Companies filing their annual corporate tax return who want their computation actually checked for available deductions and reliefs, not just formatted and submitted. This includes companies dealing with cross-border transactions requiring withholding tax handling, and companies approaching the GST registration threshold who need it monitored proactively.
Frequently Asked Questions
When is my company’s tax return due?
For most companies, the annual return (Form C-S or Form C) is due by 30 November each year. Before that, many companies also need to file an Estimated Chargeable Income within three months of their financial year end, although smaller companies with no taxable income may be exempt. We keep track of both dates for you and start preparing well ahead, so there’s no last-minute rush.
Our company made a loss. Do we still need to file?
Yes. Every company has to file, even in a loss-making year. It’s actually worth doing carefully: losses can often be carried forward to reduce tax in future profitable years, as long as certain conditions are met. Filing properly now protects that benefit.
We’re a new company. Do we pay full tax straight away?
Usually not. Qualifying new companies get a start-up tax exemption on part of their income for their first three years of assessment, and all companies get a partial exemption after that. Some years there are also Budget rebates. We check which ones apply to you each year rather than assuming.
Can you help us pay less tax?
Yes, within the rules. We make sure you claim every deduction, allowance and rebate you’re entitled to, which often makes a real difference. What we won’t do is stretch the rules or record personal expenses as business costs. If something is a grey area, we’ll explain the options and the risks honestly and let you decide. Saving a little now isn’t worth an IRAS investigation later.
What happens if we file late?
IRAS may issue an estimated assessment, which is often higher than what you’d actually owe, and late filing can lead to penalties. If you’re already late, don’t panic. Tell us where things stand, and we’ll prioritise getting the return filed as soon as possible.
What if IRAS sends us a query?
Queries are fairly common and don’t automatically mean something is wrong. If we prepared your return, we’ll handle the reply with you, explain what IRAS is asking for and help gather the supporting documents. Because we keep a record of how your computation was put together, answering is usually straightforward.
Do you also handle my personal tax as a director?
We can. For owner-directors, company and personal tax are closely linked through directors’ fees, salary and dividends. Looking at both together can help you make better decisions about how to pay yourself. If you already have someone handling your personal tax, that’s fine too.
When do we need to register for GST?
When your taxable turnover was more than S$1 million in the last calendar year, or when you expect it to be more than S$1 million in the next 12 months. Some businesses below the threshold also choose to register voluntarily. It can make sense in some situations but brings extra admin, so we’ll talk it through with you first.