Trinidad and Tobago Individual Income Tax Return (IRD Form 400 ITR)

Candidate selection

GOV-4575 ("GovSchema Standard Research"). GOV-4568 opened Trinidad and Tobago as the registry's 91st jurisdiction via tt/imd/passport-application-first-adult@1.0.0 and banked three further STRONG-candidate verticals for a future cycle in CATALOG.md's Known Gaps entry 0m: DMV (Ministry of Works and Transport Form 4 + Form 12), Business Formation (Companies Registry Form 1, plus a Form 6 sole-proprietor statement already confirmed image-only/scanned with no extractable text layer), and Taxes (Inland Revenue Division Form 400 ITR). This cycle authors the Taxes candidate: it carries no disclosed OCR blocker (unlike Business Formation's Form 6) and no disclosed broken-TLS-chain fetch workaround (unlike DMV's mowt.gov.tt), making it the cleanest of the three banked candidates to pick up first.

Reaching the live source

https://ird.gov.tt/Media/Default/IRDForms/2018/F-400ITR--2018.pdf

• Required curl -k (TLS certificate verification bypass) to reach ird.gov.tt from this session's network egress — a plain curl request without it fails at the TLS handshake (exit code 60); this is a connectivity/certificate-chain characteristic of the host, not a login/CAPTCHA/WAF content gate, and does not affect the document's own authenticity once reached.
• HTTP 200, Content-Type: application/pdf, 157,151 bytes — matches the byte count independently recorded when this candidate was first banked in GOV-4568, confirming the source has not changed since.
• sha256 of the retrieved bytes: 5db6ccfcd095f3194de69e97b348fe787c1a4c9f08561911a94fb2811ef47a36.
• PDF header %PDF-1.4 at byte 0, 13 pages, confirmed via pdfjs-dist's numPages.
• getAnnotations() returned zero AcroForm fields on any of the 13 pages — a flat, print-and-fill specimen, not an interactive form.
• Despite the filename and footer barcode reading "2018"/"V1-18400ITRP0x", the document is confirmed live and currently served from IRD's own "IRDForms" media library at the exact URL banked in GOV-4568 — the Inland Revenue Division's standing practice of keeping prior-year return templates permanently downloadable (the filer supplies the correct reporting year via the schema's own printed header, not a URL path change).

Authority attribution

The document's own header prints "GOVERNMENT OF THE REPUBLIC OF TRINIDAD AND TOBAGO, Ministry of Finance, Inland Revenue Division", and is approved by the Board of Inland Revenue under Section 76 of the Income Tax Act, Chap. 75:01. This schema attributes authority to the Inland Revenue Division (IRD, ird.gov.tt), the issuing and processing authority whose own domain hosts the form.

Extraction method

pdfjs-dist (vendored at /tmp/node_modules/pdfjs-dist) getTextContent() read every text item's raw string and transform x/y position on all 13 pages, grouped into printed rows by rounded y-coordinate and sorted by x-coordinate. The document is plain English with clean, non-rasterized embedded fonts — the text layer extracted completely and unambiguously. Pages 1-2 (the core return this schema models) were also rendered to PNG via node-canvas at 2.5x scale to visually confirm the true table/checkbox layout; unlike some other registry sources where embedded-font glyph outlines failed to rasterize in this environment, this specimen's glyphs rendered cleanly, visually confirming every checkbox ("NAME CHANGE" / "ADDRESS CHANGE"; "Resident" / "Non-Resident" / "Male" / "Female" / "Self-employed") as a plain, symmetric square glyph with no printed asymmetry between paired options.

Document structure

The 13-page form (each page footer-stamped with its own V1-18400ITRPnn code) is: page 1, the Identification Section and the start of the Tax Computation Section (Income, Lines 1-10); page 2, Deductions (Lines 11-33), Prepayments (Lines 34-41), and the General Declaration; pages 3-13, twenty lettered companion Schedules (A through T) covering specific income types and computations referenced from the main return by page number (e.g. "Page 6, Schedule E", "Page 3, Schedule B", "Page 4, Schedule C", "Page 11, Schedule R", "Page 13, Schedule T").

Scope

This v1.0.0 schema models only the 2-page core return (Identification Section, Tax Computation Section, General Declaration) — the portion every individual filer completes regardless of income type. The 20 lettered companion Schedules (A-T, pages 3-13) are excluded, following this registry's standing narrow-scoping precedent for large multi-schedule tax returns (e.g. Zambia's ITF 46_1 excluding its business/self-employment computation sections; Kazakhstan's Form 250.00 authored core-first with Schedules 250.01-06 as separate companion documents in later cycles). Each excluded schedule is referenced from a specific core-return field's own description (e.g. netIncomeFromOtherSources cites Schedule E, alimonyMaintenancePayment cites Schedule B), so the gap is visible rather than silent, and left as disclosed open backlog for a future companion-schema cycle.

Within the core return, every printed formula/subtotal line — Lines 4, 6, 10 (Income section); 14, 16, 20, 24, 25, 26, 29, 30, 32, 33 (Deductions section); 39, 40, 41 (Prepayments section) — is excluded from fields[], per this registry's standing closed decision to defer calculated/derived fields (GSP-0013 §7, founder-confirmed on GOV-302). Only the lines a taxpayer directly supplies are modelled. The sole exception is Line 15 ("Deduct Personal Allowance - $72,000"): although printed alongside formula lines, it is a fixed statutory constant available to every individual filer rather than a value derived from other lines on this form, so it is modelled as a directly-supplied required field, consistent with how this registry treats other schemas' own printed fixed-allowance constants.

Disclosed findings and interpretation choices

1. Three independent tick-box groups share one "Please tick the appropriate box" instruction — Resident/Non-Resident, Male/Female, and a standalone Self-employed box — confirmed via the page 1 render: the first two are modelled as mutually-exclusive enum fields (residencyStatus, sex); Self-employed is modelled as an independent isSelfEmployed boolean, since the form prints it as a third, separate checkbox rather than a third option of either enum.
2. **tradeName/typeOfBusiness/addressOfBusiness* are gated requiredWhen isSelfEmployed equals true**, per the form's own printed qualifier "(IF ANY) SELF EMPLOYED ONLY" directly beside the Trade Name box.
3. personalAllowance (Line 15) is modelled required, not excluded as a computed total — see Scope above for the distinction drawn between a fixed statutory constant and a line genuinely derived by formula from other lines.
4. covenantedDonations (Line 13)'s own printed 15%-of-Line-10 ceiling is disclosed in its description but not enforced as a validation maximum, since Line 10 (Total Income) is itself an excluded computed total this schema does not carry a value for.
5. declarationDate collapses the declaration's own printed "day of .... 2019" blank into one ordinary date field rather than splitting day/month/fixed-year sub-fields or introducing a schema edition axis, consistent with this registry's kz/kgd/*/ua/dps/* tax-return precedent of modelling a filing year as an ordinary data value on a single, undated generic schema rather than a new edition per tax year.
6. Every Income/Deductions/Prepayments line (Lines 1-3, 5, 7-9, 11-13, 17-19, 21-23, 27-28, 31, 34-38) is modelled required: false: the form's own "To Nearest Dollar, Omit Cents/Commas" column header carries no accompanying "enter NONE if not applicable" instruction, but every line is visibly one of many alternative income/deduction/prepayment categories a given filer may simply not have — the same left-blank-if- inapplicable convention this registry's bw/burs/individual-tax-return and zm/zra/individual-income-tax-return precedents already apply to their own analogous income-category lines.
7. Excluded as official-use-only fields, not applicant-supplied data: page 2's "FOR OFFICIAL USE ONLY" box ("Place Date Received Stamp Here").

Conformance

3 valid mock scenarios — valid-employed-resident (a resident PAYE employee with employment income, personal allowance, and a signed declaration, no self-employment or schedule-referenced lines populated); valid-self-employed-with-deductions (a resident, self-employed filer exercising isSelfEmployed's four requiredWhen-gated business fields plus several deduction lines); and valid-non-resident-with-schedule- referenced-income (a non-resident filer exercising the Schedule- referenced lines — netIncomeFromOtherSources, alimonyMaintenancePayment, taxCredits, businessLevyLiability, totalIncomeTaxQuarterlyInstalmentsPaid, totalBusinessLevyQuarterlyInstalmentsPaid) — plus 8 mutation-control fixtures (one missing statically-required field from each of birFileNo, lastName, firstName, occupationOrProfession, dateOfBirth, personalAllowance, declarantName, signatureOfTaxpayerOrAuthorisedAgent — 8 fixtures) and one unknown-field-rejected fixture, committed under conformance/tt/ird/individual-income-tax-return/1.0.0/.

An ephemeral, from-scratch conformance checker (deriving required/ requiredWhen rules directly from this schema's own fields[], discarded after use, not committed) ran all 12 fixtures: all 3 valid scenarios at 0 errors, all 8 static-required mutation controls each raising exactly 1 error, the unknown-field fixture correctly rejected, and confirmed every requiredWhen field reference resolves to a real field name (0 dangling references). Validated clean with node tools/validate.mjs and node tools/validate-ajv.mjs, individually and as part of the full registry run.