Portuguese companies must file the Modelo 22 (annual Corporate Income Tax declaration), statutorily due May 31 of the following year — for the 2026 cycle, executive Order no. 81/2026-XXV-SEAF extended this to June 30, 2026. The IES (Informação Empresarial Simplificada) combines commercial registry, central-bank statistical, and annual accounting data, due digitally via the Portal das Finanças by July 15 of the following year. SAF-T billing files (structured electronic invoicing data) must be uploaded monthly by the 5th of the following month. Directors must convene an annual general assembly to approve financial balances within 3-4 months of fiscal year-end, with approved balance sheets registered publicly via the IES portal. Late tax filing carries fines from €150 to €10,000; using uncertified billing software carries fines from €3,750 to €18,750.