IRAS Tax Audit Singapore: How to Prepare and Respond
Receiving an IRAS tax audit notice in Singapore can be stressful, but being selected for an audit does not automatically mean your company has made a tax mistake. The Inland Revenue Authority of Singapore (IRAS) conducts audits to check whether businesses have correctly reported their income, expenses, GST and other tax information.
A well-organised response can make the process easier. Businesses should understand what IRAS may request, gather supporting documents early, respond accurately and address any discrepancies promptly.
This guide explains how to prepare for an IRAS tax audit in Singapore in 2026, what documents may be required, common areas reviewed by IRAS, and when professional tax audit assistance may be useful.
What Is an IRAS Tax Audit?
An IRAS tax audit is a review of a business’s financial and tax records to determine whether its tax returns comply with Singapore’s tax legislation.
Depending on the circumstances, IRAS may conduct the review through correspondence, telephone discussions, interviews or a visit to the business premises. The scope of an audit depends on the case and the information IRAS requires.
IRAS states that being selected for an audit does not necessarily mean that a taxpayer has made an error. Audits are conducted as part of its compliance and risk-based approach.
An audit may examine areas such as:
- Corporate income tax returns
- GST returns and supporting records
- Revenue and sales transactions
- Business expenses and deductions
- Capital allowances
- Related-party transactions
- Accounting records and reconciliations
- Supporting invoices, receipts and contracts
- Other information relevant to the company’s tax position
Why Does IRAS Audit a Business?
IRAS uses compliance and risk-based approaches when selecting businesses for review. An audit may be carried out to verify information submitted in tax returns, examine specific transactions or assess whether the business is meeting its tax obligations.
Importantly, an audit selection should not be interpreted as proof that a company has deliberately done something wrong.
For GST audits, IRAS may review whether taxable supplies have been correctly reported, GST has been properly accounted for and input tax claims are supported by the required documentation.
What Happens After Receiving an IRAS Audit Letter?
If your company receives an IRAS audit notification, avoid ignoring it or delaying your response.
Start by reviewing the notification carefully. Pay attention to:
- The tax type involved.
- The Years of Assessment or accounting periods under review.
- The documents requested.
- Any specific transactions or issues mentioned.
- The deadline for responding.
- The contact details of the IRAS officer handling the matter.
IRAS may request information through written correspondence, telephone interviews or meetings. For certain audits, officers may also visit the company’s premises and examine accounting records.
A practical first-response checklist
Once an audit notice arrives:
Step 1: Read the request carefully
Identify exactly what IRAS has asked for instead of immediately sending large volumes of unrelated documents.
Step 2: Check the response deadline
Make sure someone in the company is responsible for monitoring the deadline and coordinating the response.
Step 3: Inform your accountant or tax adviser
If your business already works with an accounting or tax professional, involve them early.
Step 4: Secure the relevant records
Collect the accounting, banking, invoicing, payroll and tax information relevant to the audit period.
Step 5: Reconcile the information
Check whether the accounting records agree with the submitted tax returns before responding.
Step 6: Identify potential discrepancies
If an error is discovered, discuss the appropriate disclosure or correction process with a qualified tax professional.
Documents to Prepare for an IRAS Tax Audit
The documents required will depend on the scope of the audit. IRAS explains that auditors may examine source documents, accounting records, financial information, bank statements and other transaction-related records.
For a corporate income tax review, a company may need to organise:
- Accounting records
Prepare documents such as:
- General ledger
- Trial balance
- Profit and loss statement
- Balance sheet
- Supporting schedules
- Journal entries
- Bank reconciliations
- Sales and revenue records
These may include:
- Sales invoices
- Customer contracts
- Credit notes
- Receipts
- Sales reports
- Bank receipts
- Revenue reconciliation schedules
The objective is to demonstrate how reported revenue was calculated and recorded.
- Business expense documentation
Keep supporting evidence for significant expenses, including:
- Supplier invoices
- Payment records
- Contracts
- Receipts
- Expense claims
- Supporting correspondence
An expense appearing in the accounting system does not by itself establish that it qualifies for tax deduction. Appropriate supporting records are important.
- Fixed assets and capital allowances
If the business claims capital allowances, organise the relevant:
- Fixed asset register
- Purchase invoices
- Disposal records
- Capital allowance computations
- Supporting documentation
- Payroll and remuneration records
Depending on the audit scope, IRAS may examine employee or director remuneration and related records.
Keep relevant payroll reports, remuneration schedules and supporting filings properly organised.
- Bank statements
Bank statements and reconciliations can help establish the connection between accounting entries and actual transactions.
IRAS notes that bank statements may form part of the records examined during an audit.
GST Audit: What Should Singapore Businesses Check?
GST-registered companies should pay particular attention to the accuracy and completeness of their GST records.
IRAS may examine whether:
- GST was charged correctly.
- Output tax was properly accounted for.
- Input tax claims are supported.
- Sales and purchases were accurately reported.
- Supplies were classified correctly.
- GST returns agree with the underlying accounting records.
IRAS states that GST audits are conducted using a risk-based approach and that businesses selected for review are not necessarily assumed to have made GST errors.
Before responding to a GST audit, consider reconciling:
Accounting records → GST reporting → invoices → payment records
Any unexplained differences should be investigated before the company provides its final response.
Common Areas That May Require Closer Review
Every audit is different, but businesses should pay attention to transactions where the accounting treatment and tax treatment may differ.
Examples include:
Entertainment expenses
Make sure there is sufficient documentation showing the nature and business purpose of the expenditure.
Motor vehicle expenses
Check whether the claimed expenses are allowable under the applicable tax rules and whether private and business use have been properly distinguished.
Personal expenses paid by the company
Transactions that are personal in nature should not simply be treated as business expenses because they were paid using a corporate bank account.
Related-party transactions
Companies should maintain appropriate documentation for transactions involving related entities and consider applicable transfer pricing requirements.
Revenue completeness
Businesses should be able to reconcile reported revenue with accounting records and other relevant transaction information.
GST treatment
Incorrect GST classification, unsupported input tax claims or incomplete reporting can create additional tax exposure.
These areas should be reviewed based on the facts of the individual business rather than assuming that every transaction will receive the same tax treatment.
What Should You Do During an IRAS Audit?
Communication is an important part of the audit process.
IRAS expects businesses to provide timely, complete and accurate responses and to cooperate with requests for information.
Do:
- Respond within the required timeframe.
- Provide accurate information.
- Keep documents organised.
- Ask for clarification when a request is unclear.
- Keep records of communications and documents submitted.
- Escalate technical tax questions to an appropriate professional.
Avoid:
- Ignoring correspondence.
- Guessing when you do not know the answer.
- Providing inconsistent explanations.
- Altering or creating documents after the fact.
- Sending incomplete information without explaining what is missing.
- Making unsupported tax arguments.
The safest approach is to make sure every response can be supported by reliable records.
What If IRAS Finds an Error?
An audit may result in no adjustment, an adjustment to the company’s tax position or other compliance action, depending on the findings.
Where IRAS identifies an adjustment, the company should understand:
- What transaction or tax treatment is being questioned.
- How the adjustment was calculated.
- What supporting evidence is available.
- Whether additional tax or penalties apply.
- Whether there are grounds for an objection or further discussion.
IRAS explains that where errors are identified, assessments and other consequences may arise depending on the circumstances. Businesses that disagree with an assessment should follow the applicable objection procedures and deadlines.
Can You Make a Voluntary Disclosure?
If a business discovers an error before or during its compliance process, it may need to consider whether a voluntary disclosure is appropriate.
IRAS has a Voluntary Disclosure Programme (VDP) under which qualifying disclosures may receive reduced penalties. Eligibility and the applicable treatment depend on the circumstances and the requirements of the programme.
Businesses should therefore avoid assuming that every error qualifies for the same penalty treatment. A tax professional can help assess the appropriate disclosure route.
How Long Should Singapore Businesses Keep Tax Records?
Proper record keeping is an important part of tax compliance.
Businesses should maintain sufficient documentation to support their accounting entries, tax filings and claims. The precise retention requirement can depend on the type of tax and records involved.
Good record management also makes it easier to respond when IRAS requests information.
A practical system should allow your finance team to quickly locate:
Invoice → accounting entry → payment → tax treatment → supporting documentation
Rather than waiting for an audit before checking your records, periodic internal reviews can identify problems earlier.
How to Reduce the Stress of an IRAS Tax Audit
There is no way to guarantee that a business will never be selected for an audit. However, companies can make the process more manageable by maintaining good accounting and tax controls throughout the year.
Consider implementing these practices:
Keep accounting records up to date
Avoid allowing months of unreconciled transactions to accumulate.
Reconcile regularly
Compare bank accounts, sales, purchases, GST and accounting records periodically.
Maintain supporting documents
Do not rely solely on accounting software entries. Retain invoices, contracts, receipts and other evidence supporting significant transactions.
Review unusual transactions
Large one-off expenses, related-party transactions and unusual accounting entries should receive appropriate attention.
Separate business and personal expenditure
This makes both accounting and tax reviews easier to manage.
Review tax filings before submission
A pre-filing review can identify discrepancies before they become more difficult to explain.
Get professional assistance when necessary
Tax audits can involve detailed technical questions. Professional assistance can help businesses organise records, assess tax issues and manage communication with IRAS.
How WLP Can Help With an IRAS Tax Audit
If your business has received an IRAS query, audit notification or tax investigation request, professional support can help you navigate the process.
WLP provides accounting and tax services in Singapore, including IRAS tax audit assistance, GST audit services, tax advisory and tax investigation support. Its published services include assistance with documentation, compliance and communication with IRAS.
WLP’s tax audit support can be relevant when a business needs assistance with areas such as:
- Reviewing an IRAS audit or query letter
- Preparing supporting accounting and tax documents
- Reviewing potential tax discrepancies
- Assisting with IRAS correspondence
- GST audit support
- Tax audit and investigation assistance
- Reviewing tax compliance processes
WLP states that its team has experience supporting businesses through IRAS tax audits and investigations, including situations involving query letters and inspections.
For businesses that want to strengthen their accounting and compliance processes before an audit occurs, WLP also provides accounting, bookkeeping and tax compliance services.
IRAS Tax Audit Singapore: Frequently Asked Questions
Does receiving an IRAS audit notice mean my company did something wrong?
No. IRAS states that being selected for an audit does not necessarily mean that the business has made a mistake. Audits are part of IRAS’s tax compliance activities.
What does IRAS check during a tax audit?
The exact scope varies. IRAS may examine accounting records, source documents, bank statements, invoices, receipts and other information relevant to the tax return or transactions under review.
Can an accountant represent my company during an IRAS audit?
A company can engage professional tax or accounting advisers to assist with its tax matters. The extent of representation and the information required will depend on the nature of the audit.
What happens if IRAS finds an error?
IRAS may make adjustments to the relevant tax assessment and penalties or other consequences may apply depending on the nature of the error and applicable legislation.
Should I contact a tax professional after receiving an IRAS letter?
If the request involves complicated transactions, potential tax discrepancies, GST issues, related-party transactions or significant amounts, obtaining professional advice early can help the company understand the issues and prepare a structured response.
Can WLP help with an IRAS tax audit?
Yes. WLP publishes IRAS tax audit assistance, GST audit and tax investigation services for businesses in Singapore.
Final Checklist: Preparing for an IRAS Tax Audit
Before responding to an IRAS audit request, check that your business has:
- Reviewed the IRAS notification carefully
- Identified the relevant tax periods
- Assigned someone to manage the response
- Gathered the requested accounting records
- Reconciled bank and accounting records
- Checked supporting invoices and receipts
- Reviewed significant expenses
- Checked GST records where applicable
- Reviewed related-party transactions
- Identified potential discrepancies
- Prepared clear explanations supported by documents
- Met the IRAS response deadline
- Obtained professional advice where necessary
Need Help With an IRAS Tax Audit in Singapore?
An IRAS audit is easier to manage when your records, explanations and tax position are properly organised.
If your company has received an IRAS tax audit letter, GST audit request or tax investigation query, WLP can assist with tax audit and investigation matters, documentation and communication with IRAS.
For businesses looking for professional support before responding to IRAS, early preparation can help identify documentation gaps and potential tax issues before they become more difficult to resolve.