How to Solve Problems in Singapore | Wrong Income Tax Bill, IRAS Amendments and Assessment Objections

If your Singapore personal income tax bill looks wrong, open the actual Notice of Assessment (NOA) in IRAS myTax Portal and compare the income, reliefs and tax residency status with your records. IRAS says amendments to an eligible individual tax assessment should normally be submitted through the Amend Tax Bill service within 30 days from the date shown on the tax bill.

An objection does not automatically suspend payment. IRAS says income tax must still be paid through GIRO or within one month of the tax bill, even when you disagree with the assessment. If IRAS subsequently reduces the bill and there is a credit balance, a refund can follow. This distinction between correcting the tax assessment and meeting the current payment obligation can prevent an avoidable late-payment problem.

This guide explains how to identify incorrect employer income, missing reliefs, double-counted salary, unreported freelance income and tax residency errors; how to use the right IRAS process; and what evidence to prepare. It is for individual income tax, not corporate income tax, GST or property tax, which have different procedures.

Quick answer: fix an incorrect IRAS income tax assessment

Verify the notice. Sign into the real myTax Portal independently and check the Year of Assessment (YA) and date of notice.
Identify the discrepancy. Separate missing or duplicated income, inaccurate reliefs, a residency issue or a payment record problem.
Check the correct deadline. IRAS generally requires an amendment within 30 days of the date on the Notice of Assessment.
Use the right process. For eligible changes, select Amend Tax Bill on myTax Portal.
If AIS employer-submitted income is wrong, contact the employer or relevant organisation to correct the original data instead of blindly overriding it yourself.
Keep supporting documents. Payslips, IR8A data, CPF records, business accounts and eligibility records may be relevant.
Continue paying tax on time. IRAS says you must still pay by the bill due date even if the assessment is disputed.
Check the revised NOA. Save IRAS’s outcome, any amended assessment and refund or payment adjustment.

Start with IRAS: Making Changes After Filing or Receiving Your Tax Bill.

Step 1 — Make sure you are reading the correct tax year

Singapore individual tax assessments use a Year of Assessment (YA), which generally refers to income earned in the preceding calendar year. For example, YA 2026 generally assesses income from 1 January to 31 December 2025.

A person comparing the YA 2026 tax bill with salary received during November 2026 is therefore comparing different periods. Before objecting, identify the calendar year the income relates to and the specific assessment date.

Check whether the document is a genuine tax bill, a reminder, a statement of account or another IRAS notification. A payment balance notice is not necessarily a fresh opportunity to re-file the original assessment from scratch.

Step 2 — Check the NOA rather than only the amount due

Open the assessment details through myTax Portal and inspect the underlying income figures, allowable deductions, personal reliefs and rebates, tax residency treatment and final liability.

If the total payable looks larger than expected, ask which component actually changed. An increase may arise from higher taxable income, expired relief eligibility, a change in residency treatment or a balance from another assessment.

Do not assume your employer made an error simply because the assessed amount is surprising. Check the calculations and the actual wage period before choosing the organisation to contact.

Step 3 — Understand the two main correction windows

IRAS publishes two different processes depending on whether you have received the NOA.

Before receiving the tax bill: For eligible e-filers, IRAS permits a one-time re-filing of the individual Income Tax Return by 18 April in the relevant filing season. The successful re-filing replaces the earlier submission. It must include all the required income, expenses, donations and relief details, rather than only the one item being corrected.

After receiving the tax bill: Eligible amendments go through the Amend Tax Bill digital service, generally within 30 days from the date on the NOA.

For YA 2026, the 18 April 2026 re-filing deadline is already past as of November 2026. A person holding a YA 2026 NOA now should check the amendment, prior-year correction or IRAS enquiry process appropriate to the bill’s actual date rather than assuming the normal re-filing window remains open.

These are not interchangeable buttons. One changes a tax return during the filing process; the other seeks changes to an issued assessment.

Step 4 — The 30-day deadline starts from the tax bill date

IRAS states that amendments must ordinarily be filed within 30 days from the date stated in your income tax bill. Do not calculate the period from when you happened to open the email or notice.

For example, a NOA dated 1 July gives a different calendar deadline from a NOA dated 20 July. Record the actual date, check the official portal and act promptly. Avoid assuming that contacting payroll informally pauses the objection clock.

If you discover an issue after the ordinary window, IRAS has guidance for amendments in previous years and for cases where the digital service does not cover the requested change. Contact IRAS through authenticated myTax Mail or its published support route with the specific YA and circumstances.

Step 5 — Choose the correct reason for amendment

IRAS lists several purposes for the Amend Tax Bill service, including:

Revising an individual’s declared income.
Adding or amending qualifying deductions and personal reliefs.
Claiming Parenthood Tax Rebate where the relevant account has not been created.
Requesting a change in tax residency from non-resident to resident where applicable.

Not every problem can be corrected by typing over a field yourself. Employer AIS submissions, partnership income and some tax-clearance data may depend on another organisation’s corrected filing.

Use IRAS’s guide to common filing mistakes to identify how the particular field entered your assessment.

Step 6 — If your employer’s income figure is wrong

Under the Auto-Inclusion Scheme (AIS), participating employers transmit employment income details to IRAS. When AIS information is incorrect, IRAS advises employees to contact their employer to clarify and arrange correction. The employer or submitting organisation must correct the relevant original information.

For example, if the employer reported S$82,000 but the correct taxable wage amount appears to be S$78,000, do not simply subtract S$4,000 in another income box without checking the classification. A bonus, benefit or Additional Wage item may explain part of the difference.

Compare the relevant employment documents, IR8A or income breakdown and the employer’s records. Ask payroll to identify the discrepancy and submit corrected AIS information where necessary. Keep the response.

The official Amend Tax Bill FAQ explains that data submitted by AIS employers and participating organisations normally must be corrected at the source.

Step 7 — What if income is counted twice?

Double assessment may happen when a person manually declared employment income that was already included through AIS. IRAS’s FAQ explains a specific correction approach for income erroneously declared under the section for employers not participating in AIS.

Do not remove a genuine second job or additional income source because two amounts look similar. Check employer names, the specific salary periods and whether one entry is duplicated.

If the problem is genuinely a duplicated manual entry, use the appropriate amendment route and follow the form’s instructions about removal of auto-included income. Preserve a copy of the original submission and corrected assessment.

Step 8 — What if one AIS employer is missing entirely?

IRAS’s amendment FAQ specifically says that where an employer participating in AIS is missing from the tax bill, the employee should provide the details through myTax Mail, not simply enter those AIS details into the general Amend Tax Bill service.

This is different from adding income from a non-AIS employer, which may require a manual declaration through the correct filing field.

Ask the employer whether it submitted the records, and use IRAS’s published instructions for the exact situation. Correct source data helps prevent another duplicate or inaccurate assessment.

Step 9 — Check reliefs and deductions carefully

Personal reliefs and rebates can reduce tax payable, but eligibility rules differ. Common questions concern spouse, child, parent or caregiver reliefs, earned-income relief, CPF-related relief and qualifying employment expenses.

Do not assume a relief allowed in an earlier year must continue automatically. Family circumstances, dependant income limits, age, residency, shared claims and statutory changes can affect entitlement.

IRAS says employment expenses must be incurred wholly and exclusively in producing employment income for the relevant claim. Ordinary personal meals, household rent and general personal internet or phone bills are not automatically deductible.

Check the exact official criteria for the YA rather than copying a friend’s tax-return entries. A false or unsupported claim can lead to further tax and penalties.

Step 10 — What if you forgot freelance or other income?

A wrong bill can be too low as well as too high. If you earned taxable freelance, commission, rental or other income that is missing, your obligation is to correct the record rather than leave it untouched because the assessment is favourable.

Keep invoices, payment records, contracts, expense documentation and bank entries. Distinguish gross receipts from income chargeable under the appropriate tax rules. Do not assume every deposit into a bank account is taxable business revenue or that every business expense is deductible.

Self-employed taxpayers may have different record-keeping and deduction requirements. If your case involves a partnership or specialised business income, consult IRAS’s relevant guidance rather than forcing the amount into an unrelated employee-income box.

Step 11 — What if tax residency is wrong?

Singapore’s tax residency rules affect the assessment of income. A person may believe they qualify as a resident based on time worked or stayed in Singapore, but the actual rules can depend on periods of physical presence, employment and special concessions.

IRAS lists certain changes from non-resident to resident tax treatment as an eligible reason to use the Amend Tax Bill service. Gather the appropriate travel, employment and residency evidence.

Avoid assuming that holding an Employment Pass, having a Singapore bank account or renting a flat automatically proves tax residency in every relevant YA. Read IRAS’s working out tax residency guidance.

If the case involves relocation, overseas work or cross-border income, professional advice may be appropriate because a mistake can affect more than one jurisdiction.

Step 12 — You must still pay tax while an amendment is reviewed

This is the rule most likely to surprise readers. IRAS states that you must pay your assessed income tax through GIRO or within one month of the bill, even when you object to the assessment.

The fact that you filed an amendment does not automatically cancel the current payment obligation. Late payment can attract penalties if the outstanding amount is not settled according to the applicable rules.

If the amended assessment later reduces the tax, IRAS says it will refund any credit balance generally within 30 days of the amended NOA. That is why payment and assessment are best treated as two parallel processes.

What if you cannot afford the current bill?

IRAS provides GIRO options, including monthly interest-free instalments, and a way to request a longer plan in qualifying circumstances. Its tax bill guide says a taxpayer on GIRO experiencing financial difficulty can apply to manage the arrangement through myTax Portal.

Do not simply ignore the bill or stop payment because the assessment is disputed. Use IRAS’s individual income tax support to understand payment-plan options and the evidence required.

An application for a payment arrangement should be honest about current circumstances. The existence of an instalment option does not mean every requested schedule will automatically be approved.

Step 13 — What happens after you submit Amend Tax Bill?

IRAS says it reviews the request and issues an amended Notice of Assessment if a change is accepted. It publishes a usual processing time of five working days for straightforward amendments, but warns more complex cases may take up to two months.

The actual submission and evidence may require further review. Keep the acknowledgement, track communications in myTax Portal and provide additional documents only through authenticated official channels.

Do not treat the submission acknowledgement as confirmation that the original tax amount has already changed. The revised assessment or formal response establishes the result.

What if your correction concerns a previous Year of Assessment?

IRAS’s amendment FAQ describes digital service access for the current assessment, specified advance tax-clearance cases and previous years within the supported window. For some overlooked eligible reliefs, IRAS describes a period of up to four years from the end of the year in which the assessment was raised.

The relevant deadline depends on the type of correction and year, and ordinary 30-day objection rules should not be confused with every possible prior-year relief correction.

Identify the exact YA and request type before choosing the route. For older or unsupported cases, contact IRAS through myTax Mail or its genuine help channels.

Step 14 — Watch for fake IRAS refund messages

An unexpected SMS or email claiming “You are due a tax refund—verify here” may be fraudulent. IRAS has real digital services, but a genuine tax assessment should be checked by logging in to the official portal independently.

Do not reveal Singpass credentials, banking passwords or one-time codes to someone who calls claiming to process your refund. Never install software sent by an unsolicited “IRAS support” contact.

If you believe you transferred money to an imposter, treat that as an urgent bank and scam incident rather than a tax-filing issue. See How to Solve Problems in Singapore | Scammed by Bank Transfer or PayNow.

Worked example: a duplicated employer salary entry

Fictional employee Rachel checks her YA 2026 assessment and sees income from her main employer twice: once through AIS and once from a manual declaration she submitted.

She compares the amounts and employer records, identifies the duplicate entry and uses IRAS’s published procedure for removing erroneous manually declared AIS income. She keeps her acknowledgement and checks the amended NOA rather than assuming the problem is fixed immediately.

Rachel also follows the existing payment due date while the correction is processed.

Worked example: a missing relief

Fictional taxpayer Daniel sees that a child-related relief was not reflected in his assessment. He checks whether the relevant conditions were actually met in the income year and gathers the necessary documents.

He uses Amend Tax Bill within the applicable window and gives the correct details. He does not treat a previous year’s relief as proof that the current-year claim must be allowed.

The outcome depends on IRAS’s eligibility assessment, not merely Daniel’s expectation.

Worked example: the tax bill looks high but is accurate

Fictional resident Mei receives a larger NOA after changing jobs. She initially thinks the tax rate is wrong, but a review shows an additional bonus and higher taxable employment income for the relevant year.

Instead of filing an unsupported objection, she verifies the figures against payroll and then arranges payment. If paying at once would be difficult, she examines the genuine GIRO options.

Solving a tax problem sometimes means understanding an accurate bill, not necessarily changing it.

Common mistakes when correcting income tax

Comparing the wrong calendar year’s salary against the Year of Assessment.
Assuming the date you read the notice starts the 30-day amendment period.
Using the re-filing button after the filing-season deadline has passed.
Re-filing only the changed field and accidentally omitting other income or relief details.
Altering employer AIS information through the wrong field rather than seeking source correction.
Removing legitimate income merely because it seems unexpected.
Claiming a relief without confirming eligibility for the relevant YA.
Failing to pay assessed tax while an objection is pending.
Clicking an unexpected tax-refund link instead of opening myTax Portal independently.

Frequently asked questions

How long do I have to object to my personal income tax bill?

IRAS generally requires eligible amendments within 30 days from the date on the Notice of Assessment.

Can I re-file the return after submitting it?

Eligible online filers may re-file once by 18 April during the applicable filing season. After a tax bill is issued, use the appropriate Amend Tax Bill process.

What if my employer reported the wrong income?

For AIS-submitted income, clarify with the employer or submitting organisation and seek correction at the source, as IRAS instructs.

Do I have to pay while waiting for IRAS to decide?

Yes. IRAS says the tax is payable through GIRO or within one month of the tax bill even when the assessment is disputed.

Can IRAS refund me if the tax assessment is reduced?

IRAS says a credit balance is generally refunded within 30 days from an amended Notice of Assessment.

How long does an amendment take?

Straightforward cases may be handled within five working days; complex matters can take up to two months according to IRAS.

What if I forgot taxable freelance income?

Correct the omission through the appropriate reporting route and preserve supporting business and payment records. A tax bill that is too low is also a problem.

What if I missed the 30-day window?

Check IRAS’s prior-year amendment guidance and contact the agency through the authenticated portal for the appropriate procedure.

Is the same procedure used for property tax or corporate income tax?

No. This guide concerns individual income tax. Other taxes have distinct assessment and objection procedures.