The Circular Letter No. 25120/2026 replaced the outdated guidance in Circular Letter No. 33129/1993 taking into account digital invoicing practices and recent changes introduced by Decree-Law 97/2026.
Key regulatory changes
- Credit notes may only be used to amend invoice data and cannot be used to cancel invoices.
- Formal invoice errors (e.g., incorrect VAT number or customer details) must be corrected through cancellation and&n…