Anti-fraud tax AI stack — Anomaly Detector + Atena

What it is

Tax anomaly detection stack run by the Ministry of Finance combining three components operational in 2026: (1) Microsoft Anomaly Detector, in production since 2024 over the v4.4 e-invoicing receipt flow, identifying companies issuing fake invoices with no real operations (EFOS) and taxpayers artificially inflating deductions via third-party invoices (EDOS); (2) integration with TRIBU-CR, the tax platform operational since October 2025 that centralizes pre-filled returns and automated refund processing; (3) Atena, an AI module focused on the self-employed segment to monitor tax compliance over transactional data already captured by e-invoicing. The combined stack covers both general invoicing and the self-employed segment.

Context

The only Costa Rican state case with measurable, publicly reported fiscal returns. The 2026 stack evolves from a single Anomaly Detector component into integration with the new TRIBU-CR platform plus a dedicated AI module (Atena) for the self-employed segment. AI adds value on top of transactional data the State was already collecting via e-invoicing.

Official source