Registry entry

Singapore Corporate Income Tax Return (Form C-S, via myTax Portal, Year of Assessment 2026)

Prepare and e-File a Singapore-incorporated company's annual Corporate Income Tax Return using Form C-S, the Inland Revenue Authority of Singapore's (IRAS) simplified return for qualifying small companies, through myTax Portal (mytax.iras.gov.sg) for Year of Assessment (YA) 2026. Form C-S is available to a company incorporated in Singapore with annual revenue of S$5 million or below that derives only income taxable at the prevailing 17% Corporate Income Tax rate and is not claiming carry-back of current-year capital allowances/losses, Group Relief, Investment Allowance, or Foreign Tax Credit/tax deducted at source; a qualifying company with revenue of S$200,000 or below may instead opt for the shorter Form C-S (Lite), which is out of scope here (see VERIFICATION.md). A company that does not meet these conditions must file Form C, which requires submission of full financial statements and tax computation and is also out of scope. This document models Form C-S's three parts: Part A (qualifying-condition declarations, return-reviewer particulars, and the financial period), Part B (the tax-adjustment computation from net profit/loss per the financial statements through to total income after donations), and Part C (supporting figures extracted from the financial statements, the capital-allowance/loss/donation shareholding-test declarations, the new start-up company tax exemption qualifying declaration, the trading-stock appropriation/conversion declaration, and the section 10L foreign-asset-disposal-gains declaration), plus the Confirmation Page's declaration and filer/contact-person details. Out of scope for this version: the Enterprise Innovation Scheme's per-activity enhanced deduction/allowance breakdown (Training, Innovation Projects with Partner Institutions, Intellectual Property Rights acquisition/licensing, IP registration, and Singapore-based R&D — Form C-S's line items 44 to 48), the section 14C Research & Development deduction sub-breakdown (line items 38-39), and Form C-S (Lite) and Form C themselves — see VERIFICATION.md for the full scope rationale. It does not submit the return, compute tax payable, or determine any refund/assessment amount — the live myTax Portal and iras.gov.sg are always authoritative.

Registry entry

sg/iras/corporate-income-tax-return-form-cs

Jurisdiction
Singapore · national
Version
1.0.0
Verification
draft
Authority
Inland Revenue Authority of Singapore

Authoritative source IRAS 'Explanatory Notes to Form C-S for Year of Assessment (YA) 2026' (explanatory-notes-to-ya-2026-form-c-s.pdf), corroborated against the IRAS 'User Guide (Company): File Form C-S/ Form C-S (Lite)' (user-guide-(tp)_file-form-c-s...pdf, published 5 May 2026) and the 'Overview of Form C-S/ Form C-S (Lite)/ Form C' and 'Guidance on Filing Form C-S/ Form C-S (Lite)/ Form C' guidance pages

Machine access

Schema document
registry/sg/iras/corporate-income-tax-return-form-cs/1.0.0/schema.jsonapplication/schema+json
Verification record
registry/sg/iras/corporate-income-tax-return-form-cs/1.0.0/VERIFICATION.mdtext/markdown
Registry catalog
registry/index.jsonone record per schema id

Field reference

55 fields across 5 steps, read from the published schema.json, with names, types, requiredness, and validation as the document states them. The live government form remains the authoritative source.

Access and eligibility

  • hasCorppassApproverOrPreparerAccess boolean required

    myTax Portal's File Form C-S/ Form C-S (Lite) digital service requires the filer to be authorised by the company as an Approver (can submit directly to IRAS) or Preparer (can only submit to an Approver for their review and onward submission) for Corporate Tax filing in Corppass.

  • companyUen string required

    The company's Unique Entity Number, required together with Singpass to access the File Form C-S/ Form C-S (Lite) digital service.

    classification: pii
  • yearOfAssessment integer required

    The Year of Assessment being filed. Income is assessed on a preceding-year basis: for a company with a 31 Mar financial year-end, the basis period for YA 2026 is 1 Apr 2024 to 31 Mar 2025.

    range: 2023–2026
  • revenueForPeriod number required

    The company's gross revenue for the financial period, entered at the 'Form Type Selection' page before Form C-S itself. It is compulsory and determines which return the filer may use: if revenue exceeds S$5 million, Form C-S is not offered and Form C must be filed; if revenue is S$200,000 or below, the filer may additionally choose the shorter Form C-S (Lite) (out of scope for this document) instead of Form C-S. This document targets the S$200,000-to-S$5,000,000 band, where Form C-S's Part A is shown directly.

Part A — Qualifying conditions, reviewer, and financial period

  • qualifiesRevenueThreshold boolean required

    Revenue is the gross amount of income derived by the company from its principal activities in the basis period for the YA, excluding separate source income such as interest. For an investment holding company, revenue refers to its investment income.

  • qualifiesOnlyStandardRateIncome boolean required

    The company must not derive tax-exempt income (except one-tier exempt Singapore dividends and/or specified foreign-sourced income exempted under section 13(8)) or income taxable at concessionary tax rates. A company in a tax-loss position may still file Form C-S if it meets the rest of the qualifying conditions.

  • qualifiesNoExcludedClaims boolean required

    Combines four exclusions (Notes 3a-3d): carry-back of current-year unutilised capital allowances/trade losses against a prior YA's assessable income; Group Relief surrender to another group company; Investment Allowance for approved capital expenditure; and Foreign Tax Credit or Section 45 tax deducted at source.

  • returnReviewedByAccreditedTaxProfessional boolean required

    A reviewer can be a tax agent's staff or an in-house tax professional whose role is to review the return's corporate income tax treatment before submission. Where there are multiple accredited reviewers, provide the details of any one reviewer.

  • reviewerName string optional

    Name of the SCTP-accredited reviewer.

    classification: pii
  • reviewerScptMembershipNumber string optional

    The reviewer's Singapore Chartered Tax Professionals Limited membership number.

  • financialPeriodStartDate date required

    Start of the financial period this return is based on. myTax Portal pre-fills this from IRAS' record; amend it if it differs from the company's financial statements.

  • financialPeriodEndDate date required

    End of the financial period this return is based on. myTax Portal pre-fills this from IRAS' record; amend it if it differs from the company's financial statements.

  • functionalCurrency string optional

    The currency the company reports in. Most companies report in Singapore dollars (SGD); a non-SGD functional currency changes how certain pre-filled donation figures (Items 19a/19b) may be adjusted. Defaults to SGD if not otherwise stated.

Part B — Tax adjustments

  • netProfitOrLossBeforeTax number required

    Total Income less Total Expenses, extracted from the Statement of Comprehensive Income (Profit & Loss Statement). Pre-filled with '0'; enter the correct amount if not '0'.

  • separateSourceIncome number required

    Total income other than from the company's principal activity or trade, e.g. rent from real property, fixed deposit interest, and other non-trade taxable income (detailed further in Items 14a, 15, and 16). Excludes exempt one-tier dividend income, which belongs in Item 3.

  • nonTaxableIncome number required

    Examples: exempt one-tier dividend income, section 13(8) exempt income, gain on disposal of fixed assets, and specifically exempted receipts such as Jobs Support Scheme and Enterprise Innovation Scheme cash payouts.

  • nonTaxDeductibleExpenses number required

    Expenses not wholly and exclusively incurred in the production of income, not revenue in nature, or prohibited under the Income Tax Act 1947 — e.g. depreciation, donations, fines and penalties, private expenses, S-plate car expenses.

  • renovationRefurbishmentDeductionS14N number optional

    Qualifying renovation/refurbishment expenditure (e.g. general electrical installation and lighting, doors, windows, fixed partitions, flooring, wall covering, and from YA 2025 designer/professional fees) not involving structural changes requiring Commissioner of Building Control approval, subject to a S$300,000 cap for every fixed 3-year period (first period YA 2025-YA 2027).

  • enterpriseInnovationSchemeDeductions number optional

    Total enhanced deductions claimed under the EIS (available YA 2024-2028) across qualifying activities: training, innovation projects with partner institutions, acquisition/licensing of IP rights, registration of IP, and qualifying R&D undertaken in Singapore. The per-activity qualifying-cost breakdown (Items 44-48) is out of scope for this document — complete it only if making a claim; see VERIFICATION.md.

  • item8FurtherOrOtherDeductions number optional

    Expenditure qualifying for further deductions not included in Items 1 or 6 — e.g. IP protection costs (section 14A), approved trade fairs/exhibitions (section 14B), R&D expenditure (section 14D(1)), overseas investment development (section 14H), IP in-licensing (section 14U), and pre-commencement expenditure (section 14R).

  • balancingCharge number optional

    Arises when a fixed asset on which capital allowances were previously claimed is sold or ceases to be used, and the sale proceeds exceed the tax written-down value; restricted to the capital allowances previously allowed on the asset.

  • unutilisedCapitalAllowancesBroughtForward number optional

    Pre-filled by myTax Portal based on the amount IRAS carried forward for the preceding YA. Declare a different amount in the Company's Declaration box if the company's own records differ.

  • currentYearCapitalAllowances number optional

    Capital allowances on plant/machinery used in the trade or business, including allowances on hire-purchase equipment, previously-deferred allowances now claimed, EIS enhanced allowances (see Item 7), industrial building allowances, land intensification allowances, IP rights writing-down allowances, and balancing allowances.

  • unutilisedLossesBroughtForward number optional

    Pre-filled by myTax Portal based on the amount IRAS carried forward for the preceding YA. Declare a different amount in the Company's Declaration box if the company's own records differ.

  • grossRentalIncome number optional

    Total rental income for the financial period.

  • deductibleRentalExpenses number optional

    Revenue expenses directly incurred to earn the rental income, e.g. loan interest, agent's commission, insurance, property tax, repair and maintenance. Excludes industrial building allowances and land intensification allowances (Item 12).

  • interestIncome number optional

    Enter '0' if the amount is negative, as expenses in excess of interest income are disregarded.

  • otherTaxableIncome number optional

    Enter '0' if the amount is negative, as expenses in excess of other income are disregarded.

  • unutilisedDonationsBroughtForward number optional

    Pre-filled based on the amount IRAS carried forward for the preceding YA, less any donations from the fifth-preceding YA that have expired. Declare a different amount if the company's own records differ.

  • currentYearDonations number optional

    Pre-filled from current-year qualifying local donations to approved Institutions of a Public Character, auto-included from those institutions. Upward adjustment is only permitted for companies using a non-SGD functional currency.

  • currentYearOverseasDonations number optional

    Tax deduction for qualifying overseas donations under the Overseas Humanitarian Assistance Tax Deduction Scheme (OHAS) and/or the Philanthropy Tax Incentive Scheme for Family Offices (PTIS), capped at 40% of statutory income if it would otherwise exceed that.

Part C — Information from financial statements

  • revenue number required

    The company's main source of income (for an investment holding company, its investment income, e.g. dividend or interest income). Pre-filled from the amount entered at the Form Type Selection page; revise it here if needed.

  • grossProfitOrLoss number required

    Revenue less cost of goods sold (COGS). If COGS is nil, gross profit equals revenue.

  • directorsFeesAndRemuneration number optional

    All fees and payments made to directors — salaries, leave pay, commissions, bonuses, gratuities, allowances, CPF. Excludes benefits-in-kind, medical expenses, and cash allowances in lieu of medical expenses.

  • totalRemunerationExcludingDirectorsFees number optional

    Total employees' remuneration (salaries, leave pay, commissions, bonuses, gratuities, allowances, CPF) excluding Directors' Fees, benefits-in-kind, medical expenses, and cash allowances in lieu of medical expenses.

  • medicalExpenses number optional

    Deductible medical expenses (including cash allowance in lieu of medical expenses and medical insurance), capped at 1% of total employees' remuneration (2% if qualifying inpatient medical benefit conditions are met).

  • transportTravellingExpenses number optional

    Transport/travelling expenses as per the financial statements.

  • entertainmentExpenses number optional

    Entertainment expenses as per the financial statements.

  • inventories number optional

    Also known as stocks/goods. Enter at gross if available in the financial statements, otherwise net of provision.

  • tradeReceivables number optional

    Also known as trade debtors/accounts receivables. Enter at gross if available in the financial statements, otherwise net of provision.

  • changeInPrincipalActivities boolean required

    To deduct unutilised capital allowances brought forward, there must not be a change in the company's principal activities during the basis period. Select 'N.A.' equivalent (false/not claimed) if unutilised amounts brought forward are not claimed against current-YA income.

  • substantialChangeInShareholders boolean required

    Unutilised capital allowances/losses/donations can only be deducted against current-year income if at least 50% of shareholdings are held by the same ultimate shareholders as at the relevant dates (the 'shareholding test').

  • waiverOfShareholdingTestApplied boolean optional

    Where there is a substantial change in shareholders, the company may apply to the Comptroller for a waiver of the shareholding test under sections 23(5), 37(16), 37D(15), or 37O(22) of the Income Tax Act 1947, if the change is not tax-motivated.

  • claimsStartupTaxExemption boolean required

    The scheme provides tax exemption for a new start-up's first 3 consecutive YAs (75% exemption on the first S$100,000 of normal chargeable income, 50% on the next S$100,000), if the company is incorporated in Singapore, is Singapore tax-resident for the YA, and its total share capital is beneficially held directly by no more than 20 shareholders (all individuals, or at least one individual holding at least 10% of issued ordinary shares). Investment-holding and property-development companies incorporated after 25 February 2013 are not eligible (but may claim partial tax exemption instead).

  • hasTradingStockAppropriationOrConversion boolean required

    A change of use of trading stock occurs when stock intended for sale is instead used for other purposes (e.g. retained as a fixed asset); a conversion occurs when a non-trade/capital asset is subsequently converted to trading stock for sale. If yes, the company must submit the AC Reporting Form via the Submit Document digital service — see the acReportingForm document entry.

  • foreignAssetDisposalGains10L enum required

    Whether the company is a covered entity under section 10L that disposed of/sold a foreign asset during the basis period. Select 'Not Applicable' if foreign-sourced disposal gains (FSDGs) are derived solely from foreign intellectual property rights, or if the company is not a covered entity under section 10L.

    enum: yes | no | not_applicable
  • foreignAssetDisposalGainsAmount number optional

    The amount of foreign-sourced disposal gains derived during the basis period for the current YA. May be left as 0 if the entity is excluded under section 10L(8) and Item 41a is 'No'.

  • foreignAssetDisposalGainsRemitted number optional

    The amount of foreign-sourced disposal gains remitted to Singapore during the basis period for the current YA.

  • item37DeductionForRnDExpenditure number optional

    Total expenditure (net of government/statutory board grants) incurred on R&D activities conducted wholly in Singapore (in-house or outsourced), wholly overseas (related to trade), mixed Singapore/overseas activities, or under a cost-sharing agreement. The Singapore-only and staff-cost-cap sub-breakdown (Items 38-39) is out of scope for this document; see VERIFICATION.md.

Confirmation page — declaration and submission

  • declarationConfirmed boolean required

    Confirms the Confirmation Page's declaration that the information entered is correct, before submission.

  • filerName string required

    Name of the person completing and submitting the filing.

    classification: pii
  • filerDesignation string required

    The filer's position/designation at the company (e.g. Director, Finance Manager, tax agent staff).

  • filerContactNumber string required

    Contact telephone number for the filer.

    classification: pii
  • filerEmailAddress string required

    Contact email address for the filer.

    classification: pii
  • submissionRole enum required

    An Approver submits the return directly to IRAS. A Preparer can only 'Submit to Approver', who must then review and submit it; a Preparer's submission is retained in the Portal (pending the Approver's action) for 21 days or until the filing due date of 30 Nov, whichever is later.

    enum: approver_submits_to_iras | preparer_submits_to_approver

Verification record

This file is the source-review record for this document version, per the manual-source-review-v1 practice. It documents the provenance of the published fields and flow and states the current verification claim honestly.

Current claim

  • status: draft
  • verification.method: manual-source-review-v1
  • verification.lastVerifiedAt: 2026-07-05

Every field and document was read directly from the text layer of IRAS' own current-cycle Form C-S materials for Year of Assessment (YA) 2026. It remains draft, not verified, because the live myTax Portal wizard could not be walked interactively — see "What is NOT yet independently verified" below.

Access notes

  • https://www.iras.gov.sg/docs/default-source/uploadedfiles/pdf/explanatory-notes-to-ya-2026-form-c-s.pdf ("Explanatory Notes to Form C-S for Year of Assessment (YA) 2026") was fetched directly, HTTP 200, genuine text layer, extracted in full with pdfjs-dist's getTextContent (13 pages, no OCR needed). This is the primary source: it documents every numbered Item on Form C-S, the three Part A qualifying conditions, and a fully worked "Computation of Tax Payable Annex" example.
  • https://www.iras.gov.sg/docs/default-source/uploadedfiles/pdf/user-guide-(tp)_file-form-c-s....pdf ("User Guide (Company): File Form C-S/ Form C-S (Lite)", published 5 May 2026) was fetched directly, HTTP 200, genuine text layer, extracted in full (41 pages). It is a screenshot-plus-caption walkthrough of the actual myTax Portal wizard; used to confirm each Part's on-screen grouping and step order, the Form Type Selection revenue gate, which line items the portal computes automatically (so they are correctly excluded from fields[], see below), and the Confirmation Page's declaration/filer fields and Submit vs. Submit-to-Approver branching.
  • https://www.iras.gov.sg/taxes/corporate-income-tax/form-c-s-form-c-s-(lite)-form-c-filing/overview-of-form-c-s-form-c-s-(lite)-form-c and the sibling .../guidance-on-filing-form-c-s-form-c-s-(lite)-form-c page were both fetched directly as raw HTML (HTTP 200) and stripped of markup in this sandbox — not summarized by an intermediate small model — per this project's established discipline (see memory: gov-source-fidelity-verification) of not trusting a WebFetch summary alone for a field-bearing government page; a first WebFetch call on the overview page returned only navigation-menu boilerplate and explicitly said the field/eligibility content "was not included in the excerpt", confirming that discipline was necessary here, not just precautionary.
  • mytax.iras.gov.sg (the live portal) requires Singpass/Corppass authentication and was not reached in this sandbox — the same constraint already recorded for sg/iras/individual-income-tax-return-formb1, sg/ica/passport-application, and sg/acra/sole-proprietorship-registration.

Sources examined

  • Document (id, version): sg/iras/corporate-income-tax-return-form-cs / 1.0.0
  • Spec version: GovSchema 0.3.0
  • Authority: Inland Revenue Authority of Singapore (IRAS)
  • Primary source (directly retrieved, HTTP 200, text layer extracted verbatim with pdfjs-dist): "Explanatory Notes to Form C-S for Year of Assessment (YA) 2026"
  • Corroborating source (directly retrieved, HTTP 200, text layer extracted verbatim with pdfjs-dist): "User Guide (Company): File Form C-S/ Form C-S (Lite)", published 5 May 2026
  • Corroborating source (directly retrieved, HTTP 200, raw HTML stripped of markup): "Overview of Form C-S/ Form C-S (Lite)/ Form C" and "Guidance on Filing Form C-S/ Form C-S (Lite)/ Form C" guidance pages
  • Retrieved / reviewed: 2026-07-05
  • Reviewer: GovSchema Engineering (initial authoring source-review)

What was confirmed against the source

| Source element | Field(s) / document(s) | |---|---| | Overview page — Form C-S/ Form C-S (Lite)/ Form C eligibility-threshold table | schema description; revenueForPeriod eligibility framing | | User Guide "How to File Form C-S/ Form C-S (Lite)", Step 1 | hasCorppassApproverOrPreparerAccess, companyUen | | User Guide "Form Type Selection", Steps 1-2 | revenueForPeriod | | Explanatory Notes Part A, Notes 1/2/3a-3d | qualifiesRevenueThreshold, qualifiesOnlyStandardRateIncome, qualifiesNoExcludedClaims | | Explanatory Notes / User Guide Part A — "Particulars of Person who Reviewed the Return" | returnReviewedByAccreditedTaxProfessional, reviewerName, reviewerScptMembershipNumber | | Explanatory Notes Part A — financial period statement | financialPeriodStartDate, financialPeriodEndDate, yearOfAssessment | | Explanatory Notes Item 19a; User Guide "Functional Currency & Contact Information" | functionalCurrency | | Explanatory Notes Part B, Items 1-4, 6-8, 10-16, 18-19b | netProfitOrLossBeforeTax, separateSourceIncome, nonTaxableIncome, nonTaxDeductibleExpenses, renovationRefurbishmentDeductionS14N, enterpriseInnovationSchemeDeductions, item8FurtherOrOtherDeductions, balancingCharge, unutilisedCapitalAllowancesBroughtForward, currentYearCapitalAllowances, unutilisedLossesBroughtForward, grossRentalIncome, deductibleRentalExpenses, interestIncome, otherTaxableIncome, unutilisedDonationsBroughtForward, currentYearDonations, currentYearOverseasDonations | | Explanatory Notes Part C, Items 24-32 | revenue, grossProfitOrLoss, directorsFeesAndRemuneration, totalRemunerationExcludingDirectorsFees, medicalExpenses, transportTravellingExpenses, entertainmentExpenses, inventories, tradeReceivables | | Explanatory Notes Part C, Items 33-35 | changeInPrincipalActivities, substantialChangeInShareholders, waiverOfShareholdingTestApplied | | Explanatory Notes Part C, Item 36 | claimsStartupTaxExemption | | Explanatory Notes Part C, Item 37 | item37DeductionForRnDExpenditure; rndClaimForm document (Item 8 note) | | Explanatory Notes Part C, Item 40 | hasTradingStockAppropriationOrConversion; acReportingForm document | | Explanatory Notes Part C, Item 41 | foreignAssetDisposalGains10L, foreignAssetDisposalGainsAmount, foreignAssetDisposalGainsRemitted | | Overview page — "not required to submit financial statements and tax computation together with Form C-S... should prepare these documents and be ready to submit them upon IRAS' request" | financialStatements, taxComputation documents | | User Guide "Confirmation Page [Form C-S]", Steps 1-3 | declarationConfirmed, filerName, filerDesignation, filerContactNumber, filerEmailAddress, submissionRole |

Fields deliberately NOT modelled (auto-computed by myTax Portal)

The User Guide's own Part B/Part C captions state: "The following line items will be computed automatically" and list exactly these five — confirmed against the Explanatory Notes' own "Computed as: ..." formulas for each:

| Form C-S item | Computation | Why excluded | |---|---|---| | Item 5 — Adjusted Profit/Loss before Other Deductions | Item1 − Item2 − Item3 + Item4 | portal-computed, no input box | | Item 9 — Adjusted Profit/Loss before Capital Allowances | Item5 − Item6 − Item7 − Item8 | portal-computed | | Item 14c — Net Rental Income | Item14a − Item14b | portal-computed | | Item 17 — Total Income/Losses before Donations | (Item9+Item10) − (Item11..13) + (Item14c..16) | portal-computed | | Item 20 — Total Income/Losses after Donations | Item17 − Item18 − Item19 | portal-computed |

This follows the registry's existing discipline of not modelling calculated/derived fields (spec v0.3 §16, "deferred from v0.3 by founder decision") and the precedent in ie/revenue/self-assessment-tax-return-form11s ("Tax payable... computed by ..."). By contrast, Items 11/13/18 (unutilised capital allowances/losses/donations brought forward) ARE modelled as fields even though myTax Portal pre-fills them from IRAS' own record, because both source documents describe an editable "Company's Declaration" override box for each — the filer can and sometimes must correct IRAS' record, so these are genuine (optional) inputs, not read-only projections.

Scope cuts (deferred to a future version)

  1. Enterprise Innovation Scheme (EIS) per-activity breakdown — Items 44-48. The source itself frames these as opt-in: "please complete this section only if the company is making a claim and has met the qualifying conditions" (User Guide, Part B and Part C EIS steps). This document keeps enterpriseInnovationSchemeDeductions (Item 7) and currentYearCapitalAllowances's EIS-allowance component (Item 12) in scope as plain optional totals — they sit inline in Part B's base numbering — but not the five per-activity qualifying-cost/enhanced-claim breakdowns (Training; Innovation Projects with Partner Institutions; IPR acquisition; IPR licensing; IP registration; R&D undertaken in Singapore) that would require a nested/repeating field model spec v0.3 does not have (§16, "Nested field model... still undecided").
  2. Section 14C R&D deduction sub-breakdown — Items 38-39. Item 37 (the total Section 14C deduction) is in scope; the Singapore-only portion (Item 38) and the staff-cost-and-consumables cap breakdown in excess of the $400,000 Enhanced Innovation Scheme threshold (Item 39) are out of scope for the same opt-in-claim reason.
  3. Form C-S (Lite) and Form C. Both are structurally distinct forms (Form C-S (Lite) has only 6 essential fields per IRAS' own comparison table; Form C requires full financial-statement and tax-computation submission alongside the return) and are deferred to future documents rather than modelled as editions of this one, consistent with this registry's one-document-per-distinct-process practice.

What is NOT yet independently verified

  • The live mytax.iras.gov.sg wizard was not walked screen-by-screen this cycle: it requires Singpass (individual) plus Corppass (company authorisation) login, which could not be exercised in this sandbox. Field labels here are the Explanatory Notes' and User Guide's own quoted wording/captions, not the wizard's live HTML field IDs.
  • Item 41's three-scenario FSDG reporting table (Explanatory Notes, page 9-10: how foreign-sourced disposal gains land in different Items depending on whether they are chargeable, when they are remitted, and whether the entity is excluded under section 10L(8)) is genuinely complex routing logic; this document models only the three input fields (foreignAssetDisposalGains10L/Amount/Remitted) the filer actually types, not the table's own downstream Item-12/14/16-adjustment routing, which is describing bookkeeping practice rather than a distinct form field.
  • Not authored against the v0.3 edition axis. Singapore's Year of Assessment fits none of the closed edition.scheme enum (us-tax-year/gb-tax-year/award-year, GSP-0005) — the same GSP-0019 gap already flagged for sg/iras/individual-income-tax-return-formb1 and four other jurisdictions' individual returns (see spec/proposals/0019-generalize-edition-scheme-calendar-tax-year.md). A future YA's Form C-S would ship as a new major version of this document.

Mock-data test run (Phase 4)

A complete, illustrative mock filing — "Tiong Bahru Provisions Pte. Ltd.", a Singapore general wholesale trading company, YA 2026, basis period 1 Jan 2025-31 Dec 2025, revenue S$850,000 — is recorded in conformance/sg/iras/corporate-income-tax-return-form-cs/1.0.0/application-packet.json.

The Part B/Part C tax-adjustment figures (Items 1-4, 11-15, 18-19a) deliberately reproduce, unchanged, the worked "Computation of Tax Payable Annex" example printed in the Explanatory Notes themselves (net profit $150,000 through to a published tax-payable figure of $7,898.15) — a same-numbers-in, same-numbers-out check that this schema's field set is sufficient to carry IRAS' own worked example without alteration. The computedForReference block in the packet re-derives every intermediate IRAS-computed subtotal (Items 5, 9, 14c, 17, 20, the Partial Tax Exemption, the CIT Rebate, and the final tax payable) from only this schema's fields, and the final taxPayable figure of $7,898.15 matches the source exactly.

Discrepancy found and corrected during this test run: the Annex's worked calculation actually resolves through the automatic Partial Tax Exemption available to all companies (75% on the first $10,000 of chargeable income + 50% on the next $190,000, footnote reference "v" on those two lines), reaching chargeable income after exempt amount of $69,390 and, from there, the published $7,898.15 tax payable. A separate explanation on the following page, also marked "v", shows what the exemption amount would instead be if the company claimed the New Start-up Companies scheme (Item 36) against the same $143,780 chargeable income before exempt amount — a materially larger $96,890 exempt amount — but explicitly as an "if applicable" illustration, not the calculation that produces the Annex's own published tax-payable figure. An earlier draft of the conformance packet conflated the two, setting claimsStartupTaxExemption: true and citing the $96,890 start-up figure as if it were part of the main worked chain; re-reading the Annex's own footnote wiring during this test run caught the conflation before it shipped, and the packet was corrected to claimsStartupTaxExemption: false with the Partial Tax Exemption's $74,390 figure (which is not itself a schema field — Partial Tax Exemption, unlike the New Start-up scheme, is automatic and carries no eligibility question on Form C-S).

totalFields: 55, collectedCount: 50, notApplicableCount: 5, errors: 0 — verified programmatically by re-deriving every field's effective requiredness from its required/requiredWhen member and checking exact 1:1 coverage against the packet's collectedValues/notApplicableFields.

Path to a verified claim (next step)

To advance to status: verified, a reviewer applies manual-source-review-v1 (Procedure step 2) by walking the live mytax.iras.gov.sg "File Form C-S/ Form C-S (Lite)" wizard end to end with a Singpass+Corppass-authorised test session, for a company matching this document's Form-C-S-qualifying scope; resolves any discrepancy by shipping a new schema version (immutability — VERSIONING §3); and records the outcome here plus sets status: verified with a current verification.lastVerifiedAt/nextReviewBy.

Re-verification

Per the practice's Cadence, nextReviewBy is set to 2027-01-01 (6 months) — ahead of the YA 2027 Explanatory Notes/User Guide revisions that will supersede this cycle's sources. Re-check the sources on or before that date and on any source.url change.

View the raw record (VERIFICATION.md)

Version history

  • 1.0.0 draft latest this page has verification record schema.json

Independent and non-affiliated

GovSchema is an independent, open-source project. This reference is not produced, reviewed, or endorsed by Inland Revenue Authority of Singapore or any government. The authoritative source is always the live government form and its official instructions.