Got a Letter from IRAS? What an IRAS Audit or Review Means and What to Do (2026)
By Lucas Seah, Founder of Excellence Singapore Group | Last Updated: October 2026
A letter from IRAS, even one announcing an IRAS audit, is not an accusation. IRAS itself says that being selected for an audit does not necessarily mean you have made a mistake. What matters is which kind of letter you have, what it asks for and by when, and whether there really is an error in your returns. Check that the letter is genuine, note the deadline, gather the records for the years it names, and find out whether anything needs correcting before you reply.
Short on time? Jump to what to do in the first 7 days.
Key Takeaways
- An IRAS letter is not, by itself, a criminal investigation: tax investigators usually approach you in person, with authority cards.
- Genuine IRAS notices and letters are in myTax Portal, and IRAS does not send payment links. Audit officers may email or phone you, so confirm any request by calling IRAS on the numbers on its own website.
- IRAS can generally reassess income tax up to 4 years after the year of assessment ends, and GST up to 5 years after the accounting period ends. Where there is fraud or wilful default, there is no time limit.
- For income tax, an incorrect return can attract a penalty of up to 200% of the tax undercharged, or up to 400% with intent to evade.
- Even after IRAS has written, errors outside the scope of its query or audit can still qualify for reduced penalties if you disclose them voluntarily, and full cooperation counts in your favour.
Is the letter really from IRAS?
Check this first, because scammers now copy IRAS’s audit wording. IRAS’s scam advisory lists fakes with titles such as “Notice of Tax Review” and “Income Tax Return Audit Notice”, some asking for bank details or a one-time password “to comply with a tax audit”. How to tell:
- IRAS deposits all its notices and letters in myTax Portal (mytax.iras.gov.sg), which you log in to with Singpass. A company also needs Corppass authorisation.
- IRAS does not send tax returns, notices of assessment or refund letters by email or SMS. An SMS or email alert about a notice tells you to log in to myTax Portal to view it.
- IRAS does not send messages with links to make payment. A message telling you to pay “outstanding taxes” into a bank account it designates, or through a link, is a scam.
- Audit officers may email or phone you. IRAS can run an audit by email, letter and phone interview, so an email from an officer can be genuine. Before you send documents or information, confirm it by calling IRAS on the numbers on its own website, not the ones in the email.
- Officers who visit carry IRAS authority cards. To confirm an officer’s identity, IRAS asks you to call 6351 2044 or 6351 2046.
What should you do in the first 7 days?
- Confirm it is genuine. Find the letter in myTax Portal, or call IRAS on the numbers on its own website. Do not use contact details from a suspicious message.
- Note the deadline and the scope. Write down the reply date, the tax types and years of assessment named, and exactly what IRAS has asked for.
- Do not ignore it. Not responding without a reasonable excuse counts against you when IRAS sets a penalty, failing to give information IRAS asks for can be an offence, and for an unfiled return IRAS may estimate your tax instead. If a penalty notice or a letter of composition has already arrived, our IRAS penalty waiver guide explains when it can be waived.
- Gather the records. Source documents, ledgers and bank statements for the years named and, for GST, sales and purchases listings.
- Check for errors before you reply. If something is wrong, it is better that you explain it than that IRAS finds it, and an error outside the scope of IRAS’s letter may still qualify as a voluntary disclosure. Answer exactly what is asked, and never give a false answer: giving false answers to IRAS with intent to evade tax is an offence, with a penalty of 3 times the tax undercharged, a fine of up to S$10,000 and/or up to 7 years’ jail.
- Decide who replies. If the letter is an audit notice, or you are unsure what it means, involve your accountant or tax agent before you send anything.
What kind of IRAS letter is it?
The type of letter tells you how serious the matter is and how long you have. These are the ones businesses most often receive.
| Letter | What it usually means | What to do |
|---|---|---|
| Enquiry letter (a review of your return) | IRAS is checking a return it selected and wants supporting documents or an explanation. A company with straightforward tax affairs that is selected can expect the letter by 30 Sep of the year after the year of assessment. | Reply by the deadline with exactly what is asked. If you need more time, contact the officer named in the letter before the deadline. |
| Audit notification | IRAS will examine your books and records for the years of assessment it names, by correspondence, interviews or a visit, and may widen the scope. | Gather the records for those years, check them for errors before you reply, and decide who will deal with IRAS for you. |
| A visit from tax investigators | IRAS suspects tax evasion. Investigators usually come in person, show authority cards and give you a letter stating the purpose of the visit. | Cooperate, never give a false answer, and get professional advice immediately. |
| Notice of Estimated Assessment after late or non-filing | IRAS has estimated your company’s tax because the Estimated Chargeable Income or the tax return was not filed on time. It may assume your income has gone up. | Pay within 1 month. To dispute it, object within 2 months and file the return with your objection. |
| Offer of composition for late filing | Paying a sum of up to S$5,000 per offence, and filing the overdue return by the due date, lets the company avoid prosecution for filing late. | Pay and file by the due date: paying alone does not stop legal action if the return is still not filed. A waiver is considered only if you file before that date and filed on time for the past 2 years. |
| Section 65B(3) notice to a director | IRAS requires a director personally to provide the information in the company’s overdue return. | Provide it by the due date. A director convicted of not complying faces a fine of up to S$10,000, up to 12 months’ jail, or both. |
| Notice to Attend Court (summons) | The overdue return or composition payment is still outstanding. | File and pay the composition by the deadline stated in the summons to avoid attending. If you need more time, a company representative must attend court on that date to ask for it. |
| Additional or amended assessment after an audit | IRAS has adjusted your tax, often with a penalty or an offer of composition. | Pay by the due date even if you disagree, and object within the deadline for your tax type. |
Sources: IRAS, audits by IRAS, tax assessment process and late filing of Corporate Income Tax returns, October 2026.
Review, audit or investigation: what is the difference?
A review is the lightest touch. IRAS profiles companies by the complexity of their tax affairs and the risk to revenue. Companies with straightforward affairs usually have their returns accepted with little or no adjustment, and IRAS reviews a small percentage of them under its compliance programmes, asking for supporting documents where needed. If it adjusts anything, it issues an amended Notice of Assessment.
An audit goes further. IRAS examines your accounting books, records and financial affairs to check that your returns comply with the law. It selects businesses mainly on risk, using data analytics, and also audits some at random. For GST, IRAS says it “does not assume that a business selected for audit has made GST errors”.
An investigation is a criminal matter. IRAS’s tax investigation programme deals with suspected evasion and fraud. It can involve surprise visits to your business premises, your home and your tax agent’s office, searches and interviews, and it can end in prosecution. An investigation usually takes about 15 to 24 months.
Why did IRAS pick you, and what is it checking in 2026?
IRAS runs both risk-based and random audits across all industries, using data analytics to choose which companies to look at. For GST, it selects businesses within each industry on a risk basis, and also audits some periodically to check the general level of compliance. Either way, it helps to know where IRAS is looking.
IRAS publishes the areas it is focusing on and the mistakes it keeps finding. For companies, its ongoing areas of focus include private or non-deductible expenses claimed by the company, such as family meals, holidays and groceries, and pay to directors and their family members that does not match the work they actually do, a pattern IRAS notes in family-owned companies. (Our guide to director salary versus dividends covers how to pay yourself properly.) The specific mistakes it lists from past programmes include capital allowances wrongly claimed on items such as renovation, doors and general lighting, depreciation that was not added back, and dormant companies that restart business but do not file. Its upcoming programmes cover Enterprise Innovation Scheme claims and withholding tax on payments to non-residents.
For GST, IRAS’s current audit focus is missing trader fraud, low-value GST refund claims, sales of non-residential property, and sole proprietors who under-declare their supplies. In FY2025/2026, IRAS completed more than 2,700 GST audits and recovered S$226 million, including penalties.
What happens during an IRAS audit?
IRAS tells you about an audit by letter, email or phone call, and sets out the documents it will examine and the years of assessment covered, though it can widen the scope later. The audit can run entirely by email, letter and phone interview (often called a desk audit), or IRAS may visit your premises (a field audit) or ask to meet your key staff.
On a field visit, a team of usually three or four officers starts with an interview about the size and nature of your business, its operations, who does what, and how your bookkeeping and internal controls work. They then examine:
- source documents, such as receipts, invoices, vouchers and documents from customers and suppliers;
- accounting records and schedules, on paper or electronic;
- business bank statements, and personal bank statements if required;
- any other records of transactions connected with the business.
A visit can last from a few hours to a day. Officers may take some records away for further review, or come back if records are incomplete.
For a GST audit, expect to provide sales and purchases listings in a set format, such as an Excel spreadsheet, together with supporting invoices and export documents. IRAS may also check your figures with your customers, suppliers and banks.
IRAS expects full access to your premises and records, timely and complete answers, and honesty, including disclosing any irregularities at the earliest possible time. Under section 65B of the Income Tax Act, failing to give information IRAS asks for, without a reasonable excuse, is an offence.
If your records are incomplete, IRAS will use other available information to estimate your figures, and expense or capital allowance claims without supporting documents may be disallowed. This is where everyday accounting compliance pays off.
IRAS says most audits are completed within 12 months. It explains its findings in writing or at a meeting, and if errors are confirmed, it issues a Notice of Additional or Amended Assessment and an Offer of Composition. Serious cases can be prosecuted.
How far back can IRAS go?
For income tax, IRAS can raise an additional assessment within 4 years after the year of assessment ends, under section 74 of the Income Tax Act. For GST, the limit is 5 years after the end of the accounting period, under section 45 of the GST Act. Where there is fraud or wilful default, both Acts allow IRAS to assess at any time.
| Tax | How far back IRAS can assess | Keep records for at least |
|---|---|---|
| Income tax (YA 2008 onwards) | 4 years after the year of assessment ends. For YA 2022, that is until 31 Dec 2026. | 5 years from the relevant year of assessment |
| GST (accounting periods ending on or after 1 Jan 2007) | 5 years after the end of the accounting period | 5 years from the end of the accounting period |
| Fraud or wilful default (either tax) | Any time | The same 5 years |
Sources: Income Tax Act 1947, s 74; Goods and Services Tax Act 1993, s 45; IRAS record keeping pages.
The often-repeated “five years, and it used to be seven” is the GST rule; the seven years applied to accounting periods ending before 2007. Keeping records is a separate duty, and the minimum is five years for both income tax and GST.
What are the penalties if IRAS finds an error?
The penalty depends mainly on whether IRAS finds an intention to evade tax, and on whether the error came to light through your own disclosure or through IRAS.
| Situation | Possible penalty |
|---|---|
| Incorrect income tax return, no intent to evade | Up to 200% of the tax undercharged, a fine of up to S$5,000 and/or up to 3 years’ jail |
| Incorrect GST return | Up to 200% of the GST undercharged or over-claimed, and a possible fine and jail |
| Wilful intent to evade income tax | Up to 400% of the tax undercharged, a fine of up to S$50,000 and/or up to 5 years’ jail (up to 7 years for serious fraudulent evasion) |
| Error disclosed voluntarily, meeting the qualifying conditions, within 1 year of the filing deadline | No penalty |
| Qualifying voluntary disclosure after that | Income tax: 5% of the tax undercharged for each year late. GST: a flat 5%. |
| Evasion disclosed voluntarily | May be compounded at a reduced 200% instead of prosecution, if the qualifying conditions are met |
Sources: IRAS, penalties for errors in tax returns, GST audits, investigation and Voluntary Disclosure Programme pages, October 2026.
Where there is no intention to evade, IRAS weighs your circumstances when it decides the penalty:
- Negligence. For example, repeating an error that IRAS or your tax agent had already pointed out, or not keeping proper records.
- Compliance history. Two bad compliance records within two years before the audit is completed, such as late filing or late payment, count against you.
- Cooperation during the audit. Not replying on time without a reasonable excuse, or delaying the audit, is an aggravating factor.
- Commitment to future compliance. Undertaking to improve your record keeping, use proper accounting software or engage qualified people counts in your favour.
The last two are within your control from the day the letter arrives.
Errors made by others are treated differently. If a tax bill is revised only because a platform or other intermediary sent IRAS wrong income figures, IRAS has said that taxpayers will not be penalised. It said so in October 2026, after Grab submitted corrected income records for private-hire drivers.
Can you still make a voluntary disclosure?
Yes, for some errors. Under IRAS’s Voluntary Disclosure Programme, a disclosure must be accurate and complete, and timely and self-initiated, which normally means made before IRAS sends you a query or tells you an audit or investigation has started. But IRAS’s e-Tax Guide on the programme (January 2026) adds that a taxpayer who has already received a query, or is under audit or investigation, can still qualify for reduced penalties for errors that are not directly related to the scope of that query, audit or investigation. One of IRAS’s own examples is a business that filed a GST F7 to disclose output tax errors while IRAS was auditing its input tax for the same period, and qualified.
Errors within the scope of the letter cannot qualify, but disclosing them early still matters. IRAS asks taxpayers under audit to disclose irregularities and omissions at the earliest possible time, and it takes cooperation into account when it sets the penalty. If you find an error while preparing your reply, raise it rather than wait for IRAS to find it.
If no letter has arrived yet and you have found an error, act now: a qualifying disclosure made within one year of the filing deadline attracts no penalty. For GST, the disclosure itself is usually made by filing a GST F7; our guide on how to correct GST errors explains when you need one. Our guide to the IRAS Voluntary Disclosure Programme covers the conditions, penalties and how companies file.
What if you disagree with IRAS’s assessment?
You can object, but the deadlines differ by tax and by taxpayer, and the tax is still payable while the objection is considered.
| Taxpayer | Deadline to object | Also note |
|---|---|---|
| Company (income tax) | Within 2 months of the date of the Notice of Assessment, through Revise/Object to Assessment on myTax Portal. A notice dated 5 Jan 2026 must be objected to by 5 Mar 2026. | Pay within 1 month anyway. Any excess is refunded if the assessment is revised. |
| Individual or sole proprietor, after an audit | In writing within 30 days, stating the specific grounds | The tax is still payable within 1 month of the notice. |
| GST | In writing within 30 days of the Notice of Assessment, with detailed reasons, signed and dated | If you disagree with IRAS’s decision, appeal to the GST Board of Review within 30 days. |
Sources: IRAS, tax assessment process, audits by IRAS and objecting to a GST assessment, October 2026.
Not every estimated notice needs an objection. If your company filed on time and IRAS is still reviewing a more complex return, the estimate uses your own figures and needs no objection; the final notice follows the review. An estimate IRAS raised because a return or estimate was not filed on time does need an objection, within 2 months, if you disagree with it. Our guide to the Notice of Assessment explains the different types.
Common misconceptions about IRAS audits
- “IRAS only looks at people who buy property or cars in cash.” IRAS does send query letters to individuals who buy high-value assets, asking about their source of funds. But its audits cover all industries, using data analytics and information from third parties such as customers, suppliers and banks.
- “My two businesses are separate for GST.” A sole proprietor must combine the turnover of all their sole proprietorships, whether or not they are registered with ACRA, when checking the S$1 million GST registration threshold. IRAS lists a closely related mistake under its current audit focus: GST-registered sole proprietors who believe only one of their businesses is subject to GST.
- “Small expenses do not need receipts.” Records must be kept for at least five years, and claims without supporting documents can be disallowed.
How we help with IRAS letters and audits
Excellence Singapore Group’s tax team, which brings accreditation from the Singapore Chartered Tax Professionals (SCTP) in both income tax and GST, handles IRAS correspondence, audit support and penalty mitigation, and represents businesses during IRAS audits. When a letter arrives, this is how we work:
- Send us the letter and the return it relates to, before you reply to IRAS.
- We work out what IRAS is asking and where you stand. We check your records and returns for the years named and find the weak spots before anything goes back.
- We plan the strategy. Most queries and audits need more than a reply. We decide how to present your position, what to explain, what to defend and what to correct, aiming for the best outcome the facts allow. Where it fits, that includes a voluntary disclosure for errors outside IRAS’s scope, or an objection if you disagree with an assessment.
- We deal with IRAS for you. We prepare the replies, explanations and supporting schedules, represent you during the audit, and see the case through to the final assessment.
- We fix the cause. Once the case closes, we help put right the bookkeeping or process behind the query, so the same issue does not come back.
For GST-registered businesses, we also carry out GST ASK reviews, IRAS’s self-review framework for GST compliance.
Prevention is cheaper than an audit. Our guides to common tax mistakes for SMEs and ACRA late filing penalties, which are separate from IRAS’s, cover the basics.
Frequently Asked Questions
Does an IRAS audit letter mean I did something wrong?
Not necessarily. IRAS selects businesses for audit mainly on risk, and also checks some at random, and it says being selected does not necessarily mean you have made a mistake. An audit checks whether your returns are accurate, and the outcome depends on what your records show.
How many years back can IRAS go?
For income tax, IRAS can generally raise an additional assessment within 4 years after the year of assessment ends. For GST, the limit is 5 years after the end of the accounting period. Where there is fraud or wilful default, there is no time limit. Businesses must keep their records for at least 5 years.
How do I know if an IRAS letter is real?
Log in to myTax Portal yourself and look for it there, because IRAS deposits all its notices and letters in the portal. IRAS does not send tax returns, notices of assessment or refund letters by email or SMS, and does not send payment links. Audit officers may email or phone you, so confirm any request by calling IRAS on the numbers on its website. To confirm a visiting officer’s identity, call 6351 2044 or 6351 2046.
How long does an IRAS audit take?
IRAS says most audits are completed within 12 months, depending on the standard of your records, the scope of the audit and your cooperation. A field visit can last from a few hours to a day. A tax investigation usually takes about 15 to 24 months.
Can I make a voluntary disclosure after IRAS contacts me?
Yes, for errors that are not directly related to the scope of IRAS’s query, audit or investigation: these can still qualify for reduced penalties under IRAS’s Voluntary Disclosure Programme. Errors within that scope do not qualify, but disclosing them early still helps, because IRAS takes your cooperation into account when it sets a penalty.
What happens if I ignore an IRAS letter?
It usually makes things worse. Not replying without a reasonable excuse is an aggravating factor when IRAS sets a penalty, and failing to give information IRAS asks for can be an offence. For an unfiled company return, IRAS may issue an estimated assessment, offer a composition of up to S$5,000 and summon the company and its directors to court.
Received a letter from IRAS? Reply right the first time
An IRAS letter is easier to handle when the reply is accurate, complete and on time, and harder when it is ignored or rushed. If you have received a letter, an audit notice or an estimated assessment from IRAS, or found a mistake you want to correct, talk to us before you reply and we will tell you where you stand.
