Stamp Duty
Plain English
It's a stamp duty levied on many documents, certificates, and contracts in Italy. It\'s paid either by buying a paper marca da bollo at a tobacconist or virtually inside the digital document.
Why it matters
Almost every official paper or invoice above a threshold has an imposta di bollo line. Skipping it can invalidate the document or trigger a small fine on top of the original duty.
Common confusion
On electronic invoices, the bollo is paid quarterly by the issuer to the Agenzia delle Entrate. On paper documents and many certificates, you stick a physical marca da bollo on the page.
Official source
Agenzia delle Entrate