Bollo is a stamp duty charge that may need separate handling in invoicing, especially in electronic billing workflows. In practice, it is a compliance item attached to certain documents rather than a normal line item for goods or services. Whether it must be applied depends on the document type, tax regime, and local rules.
In cyber security and digital finance controls, bollo matters because invoice data must stay accurate and traceable. If the duty is omitted, duplicated, or moved to the wrong record, the result can be a broken audit trail, payment disputes, or compliance exposure. Attackers who tamper with invoice metadata may try to hide this kind of charge, while defenders rely on validation rules, document linking, and logging to ensure the original invoice, corrections, and any credit notes remain consistent.