Challenging Tax Assessments Issued by IRAS
Receiving an unexpected tax assessment can be alarming, particularly where IRAS has increased the taxable amount, denied a deduction, imposed a penalty or questioned how a transaction was structured. The first step is not to argue informally, but to identify the assessment, the statutory route and the deadline that applies.
Tax disputes may concern income tax, GST, property tax, stamp duty or another regime. Each has its own procedure. The Notice of Assessment or decision should therefore be read carefully before any response is filed.
What issues commonly lead to disputes?
One recurring issue is whether a gain is capital or income. Singapore generally does not tax capital gains as such, but profits from a trade or an adventure in the nature of trade may be taxable. In assessing this, IRAS and the courts apply the so-called "badges of trade" — a set of indicative factors including the taxpayer's intention, the frequency and duration of similar transactions, the way the transaction was financed, any improvements made to the asset, and the circumstances of disposal. No single factor is decisive; the analysis is holistic.
Other disputes concern deductions, allowances and the tax treatment of business transactions under the Income Tax Act 1947. An expense may be rejected because it is private, capital, insufficiently supported, or not incurred in producing income. GST disputes under the Goods and Services Tax Act 1993 may involve compulsory registration, input tax claims, the character of a supply, or arrangements said to produce an artificial GST advantage.
How long do you have to object?
The deadline depends on the tax and the taxpayer. Under section 76 of the Income Tax Act, individual taxpayers generally have 30 days from the date of the Notice of Assessment to object, while companies generally have 2 months. GST assessments generally require an objection within 30 days, under section 49(1) of the GST Act. Other taxes may have different rules.
Contacting IRAS informally does not necessarily preserve the right of objection. A valid objection should identify the assessment, set out the grounds clearly and comply with the prescribed channel and deadline (via the "Revise/Object to Assessment" digital service at myTax Portal, or in writing where permitted). Note that this digital service is the practical channel through which a request is submitted, but it is distinct from the formal statutory objection under the Income Tax Act or GST Act — what is filed should make clear whether it is a mere amendment/revision request or a formal objection intended to preserve your statutory rights. A late objection may be accepted only in limited circumstances.
What should an objection contain?
A useful objection identifies each adjustment or penalty challenged, states the legal and factual grounds separately, gives the taxpayer's proposed treatment or revised amount, and attaches the contracts, accounts, invoices, computations and correspondence supporting the position. It should also explain missing records, late filing or apparent inconsistencies rather than leaving IRAS to draw its own conclusions.
IRAS may request further information during its review, and the timeframe expected for a response can vary depending on the nature of the request — taxpayers should check the specific deadline given in IRAS's correspondence rather than assume a fixed period. Failing to respond properly can result in the objection being closed or the assessment remaining in force. Records and correspondence should therefore be organised from the outset.
What happens if IRAS refuses to amend the assessment?
If IRAS issues a Notice of Refusal to Amend, the next step depends on the tax:
• Income tax disputes may proceed to the Income Tax Board of Review, generally within 30 days of the refusal.
• GST disputes may proceed to the GST Board of Review, generally within 30 days of the decision.
Appeals from a Board may reach the General Division of the High Court, but only where the appeal raises a question of law, or a question of mixed law and fact. By that stage, the taxpayer must identify the precise question in dispute and the evidence supporting the position.
What should a taxpayer do immediately?
Note the assessment date and calculate the objection deadline — 30 days for individuals, 2 months for companies, in each case running from the date on the Notice of Assessment. Preserve the filed returns, tax computations, accounts, contracts, invoices and all IRAS correspondence. Avoid creating explanations after the event where contemporaneous documents already exist, and obtain professional advice early where the issue may carry penalties or wider implications.
The practical takeaway
Tax disputes are won or lost on precision: the correct deadline, route, grounds and documents. The capital-versus-income question turns on the badges-of-trade analysis rather than a fixed rule, so the facts matter enormously. Acting early does not mean escalating immediately — it means preserving the right to challenge the assessment and presenting the strongest available case before positions become fixed.