IRAS Revise/Object to Assessment: Why Singapore’s Tax Objections Go Fully Digital by 1 July 2027

Every year, some Singapore companies discover, after their Estimated Chargeable Income (ECI) or their Form C-S, Form C-S (Lite) or Form C has already been submitted, that a figure was wrong. A capital allowance was miscalculated, a related party transaction was omitted, or the Notice of Assessment (NOA) that comes back from IRAS simply does not match what the director expected. When that happens, the company needs to revise the return or formally object to the assessment, and since 2021 the primary channel for doing so has been IRAS’s Revise/Object to Assessment digital service on myTax Portal.

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That channel is about to stop being optional. As part of the proposed Finance (Income Taxes) Bill 2026, which MOF opened for public consultation from 8 June to 1 July 2026, the government has proposed requiring companies to use IRAS’s e-service for objections and revisions, rather than paper channels. IRAS has signalled this digital-only requirement is targeted to take effect from 1 July 2027.

This guide explains what the Revise/Object to Assessment service covers, how the process works step by step, the deadlines finance teams need to track, and what changes once digital filing becomes mandatory. If your company has ever corrected an ECI figure or pushed back on a Notice of Assessment, this is the mechanism you will be using, permanently, from mid-2027.

What Is the Revise/Object to Assessment Digital Service?

The Revise/Object to Assessment digital service is IRAS’s myTax Portal facility that lets a company, or its authorised tax agent, correct figures already submitted to IRAS or formally dispute a Notice of Assessment. Depending on what a company has filed and the status of that filing, the service automatically routes the user to one of three workflows: revising an ECI, revising a Form C-S, Form C-S (Lite) or Form C that is still under review, or objecting to a Notice of Assessment once the form has been finalised.

Access is gated through Corppass. A company employee or a third party such as a tax agent must be authorised in Corppass as a Preparer for “Corporate Tax (Filing and Applications)” to draft a revision or objection, and a separate Approver must review and submit it to IRAS. This two-role structure is the same authorisation model used for other Corppass-linked filings, so if your company has already set up Corppass access for Bizfile or GST purposes, the same governance habits apply here. Companies that have not yet mapped out who holds which Corppass role should treat this as a good prompt to do so; our guide to setting up Corppass for a new company and our companion piece on who should hold which Corppass e-service role both cover the access side of this in detail.

From Optional Channel to Mandatory Requirement: The Finance (Income Taxes) Bill 2026

The Revise/Object to Assessment service already exists and has done since 2021, but using it has not, until now, been a strict legal requirement. Some companies still lodge objections using IRAS’s downloadable paper Notice of Objection form or write in directly. The Finance (Income Taxes) Bill 2026 proposes to close that gap.

What the Bill Proposes

According to MOF’s public consultation notice, the Bill proposes 20 amendments to the Income Tax Act 1947 and two to the Multinational Enterprise (Minimum Tax) Act 2024. Ten of the Income Tax Act amendments give effect to Budget 2026 measures, including the enhanced Corporate Income Tax Rebate for Year of Assessment (YA) 2026, covered separately in our guide to the YA2026 rebate enhancement. The remaining ten arise from MOF’s periodic review of the income tax system, and this group includes the proposal to require companies to use IRAS’s e-service for objections and revisions, rather than paper-based alternatives.

Timeline: Consultation, Passage and Commencement

MOF’s consultation ran from 8 June to 1 July 2026. Once feedback is reviewed and any changes incorporated, the Bill proceeds to Parliament for its readings before it is enacted. IRAS has indicated it is targeting 1 July 2027 as the date from which digital filing of revisions and objections becomes mandatory. Because the legislation was still at consultation stage at the time of writing, companies should treat this as the current target date and watch for the finalised Act and any accompanying IRAS e-Tax Guide, which will set out the definitive commencement date and any transitional arrangements, on IRAS’s own guidance page before the mandatory requirement takes effect.

Who Is Affected, and What You Can Revise or Object To

The digital service covers the great majority of correction and dispute scenarios a company will encounter. The table below sets out the three main pathways.

All three pathways cover the current YA, one advance YA, and up to four back YAs (the time-bar YA). There is no cap on how many times a company can revise or object within that window, though IRAS may ask for the reasons behind a revision rather than accept a bare figure change.

How the Digital Service Works Today: Step by Step

1. Confirm Corppass authorisation. The filer needs Preparer access, and a separate Approver must exist to release the submission.
2. Log in to myTax Portal and select Corporate Tax, then Revise/Object to Assessment. The portal automatically displays the relevant workflow based on the YA selected and what was last filed.
3. Prepare supporting documents. For a revised Form C-S/C-S (Lite), this means original and revised tax computations plus detailed profit and loss accounts. For Form C, it also extends to any revised S19B allowance declarations, R&D claim forms or related party transaction forms originally submitted.
4. Convert documents correctly. Only non-fillable PDF files are accepted, each capped at 4MB, with a 10MB total per YA submission, as set out in IRAS’s Revise/Object to Assessment FAQ. IRAS advises against saving a Word or Excel file directly as PDF; printing to PDF is the recommended method, to strip out active content.
5. Submit as Preparer, then route to Approver. The Approver must act within 14 days for an ECI revision or 21 days for a Form revision or objection, or the draft is deleted and the process must restart.
6. Retrieve the acknowledgement. If you forget to save it, it becomes retrievable under Notices > Corporate Tax in myTax Portal within three working days.

Companies correcting genuine errors, rather than disputing an assessment, should also check whether the error qualifies for IRAS’s Voluntary Disclosure Programme, which can reduce penalties for proactive disclosure made before IRAS begins a review.

Deadlines and Time Limits You Cannot Miss

The obligation to pay first and dispute later trips up more companies than any other part of this process. An objection does not suspend the payment deadline. Directors sometimes assume filing an objection buys time on the tax bill; it does not, and enforcement action can follow even while an objection is genuinely under review.

Common Mistakes Companies Make When Revising or Objecting

1. Missing the two-month objection window. Once an NOA is finalised, the clock starts immediately, not from when the director eventually reviews the notice.
2. Submitting fillable PDFs. myTax Portal only accepts non-fillable PDFs; a form saved with active fields or e-signatures embedded will be rejected.
3. Assuming Group Relief can be revised freely. A Group Relief application is final and irrevocable once submitted, and can only be revised where the company’s tax position genuinely changes from taxable to loss or vice versa.
4. Letting an Approver miss the 14 or 21 day window. A Preparer’s draft that is not approved in time simply disappears, forcing the whole submission to be redone from scratch.
5. Not authorising the correct Corppass roles in advance. Because the service requires distinct Preparer and Approver roles, a company that has only ever set up a single Corppass administrator can find itself unable to file at all until access is corrected.
6. Treating an ECI revision and a Form revision as the same thing. An ECI revision needs no supporting documents, but a Form C-S, Form C-S (Lite) or Form C revision needs the full original and revised tax computations and accounts.

Preparing Now for the 2027 Mandatory Digital Requirement

Even before the Bill is enacted, companies gain little by relying on paper channels that are already being phased out in practice. The practical preparation is straightforward: confirm that at least one Preparer and one Approver are properly authorised in Corppass for Corporate Tax filings, keep both original and revised tax computations in clean, non-fillable PDF form, and treat the two-month objection deadline and the one-month payment deadline as fixed dates on the compliance calendar. Companies still filing Form C rather than the simplified forms should also confirm their eligibility for Form C-S or Form C-S (Lite), since this affects which supporting schedules a future revision will require.

Companies using a tax agent should also confirm the agent’s Corppass authorisation extends to the Revise/Object to Assessment service specifically, not only to original filings, since the two are authorised separately. Directors weighing whether a disputed position should be resolved before a return is even filed may find our guide to IRAS advance rulings useful, since a ruling secured in advance can sometimes avoid the need for an objection altogether.

Frequently Asked Questions

Is the Revise/Object to Assessment digital service already compulsory?
Not yet. It is IRAS’s primary channel today, but the Finance (Income Taxes) Bill 2026 proposes to make it a legal requirement from 1 July 2027.

What happens if my company misses the 21 day Approver window?
The draft submission is automatically deleted from myTax Portal, and the Preparer must recreate and resubmit the revision or objection from the beginning.

Does filing an objection stop me from having to pay the assessed tax?
No. The tax stated in the Notice of Assessment remains payable within one month of the NOA date, regardless of whether an objection has been lodged.

Can a tax agent file for more than one client in a single submission?
No. Each client’s revision or objection must be submitted separately, though the portal lets an agent move straight to the next client’s filing after completing one.

How many years back can my company revise or object?
The service covers the current Year of Assessment, one advance YA, and up to four back years of assessment, known as the time-bar YA.

Preparing for a mandatory digital objections regime is largely a matter of good Corppass hygiene and disciplined record keeping rather than anything technically difficult. Companies that already keep clean tax computations on file, and know exactly who holds Preparer and Approver access, will find the 2027 transition a formality rather than a disruption.

The Editorial Team, Raffles Corporate Services