What this paper proves
The certificate says a simple thing: the civil register holds nothing that stops you marrying. No live marriage, no legal bar. It comes from the comune where your record sits, signed by the registrar, and it is an office paper rather than a court one. That single fact shapes the route it takes.
So the first move is not a queue at all. Ask the registry abroad that will marry you what they expect to see, then ask your comune for the version meant for use in another country. Learning how to legalize a Certificate of No Impediment starts with those two questions, in that order.
Why the Prefettura holds the pen
Because a registrar works for the town hall, the Prefettura signs off the certificate. The Prefettura is the state's local branch, and it keeps sample signatures of civil registrars. Court orders and papers signed before a notary follow a different road: they go to the Procura della Repubblica at the court.
Bring the paper original, buy the €16 tax stamp at a tobacconist, and hand both over together. The clerk compares the registrar's signature with the sample on file and does nothing more, so a photocopy or a scan is refused at once. To legalize a Certificate of No Impediment in Bari, plan one counter visit with the original in hand.
The consular step and the marriage file
Once the Italian stamp is on, the embassy legalization of a Certificate of No Impediment in Bari is closed at the destination country's embassy or consulate in Italy. Whether they need to see it depends on the country where the wedding will happen. Ask that registry in writing, and hold on to the reply.
Consular legalization of a Certificate of No Impediment in Italy tends to run 10–15 business days across the whole chain, or 3–5 business days when a faster slot opens. The consulate sets its own fee on top of the tax stamp and can change it, so ring them for the figure of the day.
Timing traps that break wedding plans
This certificate has a short shelf life, which is why couples get caught. Order it too early and it dies before the wedding; order it too late and the stamps do not arrive in time. Pick your date, ask both offices how fresh the paper must be, then count backwards and book the appointments in one sitting.
An embassy attestation of a Certificate of No Impediment in Bari is often filed beside a birth record and a copy of each passport. Check that every name, place and date matches across the set, letter for letter, because one differing spelling sends the whole bundle back.