CIAT e-IAD — Costa Rica’s AI anomaly detector for e-invoice fraud

Costa Rica's Dirección General de Tributación, with CIAT and Microsoft, deployed e-IAD, an open-source unsupervised machine-learning model co-developed by tax experts from seven CIAT member countries over 12 months, which analyses millions of e-invoices, tax returns and taxpayer-registry data to flag outliers and behavioural patterns consistent with organised tax evasion.

By April 2026, the system helped DGT investigators uncover a fraud network of approximately 200 taxpayers involving false vouchers totalling roughly ₡80 billion (~USD 150 million); in 2025 alone, AI-assisted audits recovered approximately ₡8 billion (~USD 15 million) deducted irregularly through unsubstantiated electronic invoices. CIAT has since deployed the same solution in Guatemala and Rio Grande do Sul, Brazil.