FATCA reporting — Form 8966 & local IGA portals: data mapping, validations & reviewer-ready evidence
Whether you report via a Model 1 portal or file Form 8966 directly with the IRS (Model 2), clean reporting hinges on stable data mapping, pre-submission validations, and a tidy evidence pack. This guide shows what to map, how to validate, and what to keep for audits and reviews.
Scope: Data flows for FATCA reporting (Form 8966 & local IGA portals), validations, receipts, corrections & governance.
Pair this with our corrections playbook.
1) Data model — the minimums to map
Keep a living data dictionary (source → target) and lock versions per filing year.
| Concept | Examples of fields | Source systems |
|---|---|---|
| Entity/Account identity | Legal name, address/country, TIN (US or foreign), GIIN (if applicable), account number | KYC/CRM, core banking |
| FATCA status | Chapter 4 classification, IGA model, sponsor/sponsored relationships | KYC/Tax master, GIIN tracker |
| Reportable values | Account balance/value, gross payments, currency, FX rate/method, reporting period | Ledger/subledgers, data warehouse |
| Contacts & consent | Email/address for notices, consent record (esp. Model 2) | KYC, e-consent platform |
Document transformations (e.g., currency conversions, country ISO codes, TIN normalization) with explicit rules.
2) Validations — before you hit “submit”
- Schema/version gate: export uses the correct schema (year & portal); reject if mismatch.
- Identity checks: name not blank; country is ISO; TIN formats; GIIN format if provided.
- Status logic: if status requires a GIIN, ensure GIIN present and found on the monthly FFI list.
- Thresholds: apply local IGA or 8966 thresholds (balances/payments) consistently.
- Currency rules: consistent FX source/date; document rounding.
- Duplicates: unique record keys; stable account identifiers per year.
Keep a one-page validation summary with counts, fails, and sign-off (maker/checker).
3) Submissions, receipts & error handling
- Package files; record hash/checksum if available; log version numbers.
- Submit via portal/IDES; capture Submission ID/receipt and any error report.
- Resolve rejects using a Corrections & Re-filings log.
- Archive receipt, error report, corrected files, and communications.
For nil filings, still keep screenshots/receipts where the portal provides them.
4) Evidence pack — what reviewers expect
- Data dictionary (source → target, transformations, versions, owners).
- Validation summary (rules, results, thresholds applied, maker/checker sign-offs).
- Submission receipts + error reports (IDs, timestamps, hashes).
- Corrections dossier (Before/After diffs, approvals, re-submission receipts).
- Policy note (governance, responsibilities, retention, privacy/consent for Model 2).
5) Quick controls (that reduce re-work)
- Freeze reporting dataset on a specific date; no silent refreshes.
- Version-lock mappings per year; change-log any updates.
- Automated GIIN match for all GIIN-dependent statuses in scope.
- Schema unit tests embedded in the build/export pipeline.
- Maker/checker approvals for submissions and all corrections.
Reporting pack (starter templates)
Data dictionary (XLSX), validation checklist (PDF), submission receipts log (XLSX).
Data dictionary (XLSX), validation checklist (PDF), submission receipts log (XLSX).
Want your reporting flow QA’d?
We map sources, lock validations, dry-run submissions, and package a clean dossier with receipts.
We map sources, lock validations, dry-run submissions, and package a clean dossier with receipts.