What the wedding office abroad is asking for
A registrar abroad will not marry you on trust. It asks for a paper from your own state saying that nothing in law stops the wedding. In Italy that is the certificato di nulla osta al matrimonio, sometimes issued instead as a certificato di stato libero. This page sets out how to legalize a Certificate of No Impediment issued in Rome.
Where the paper comes from
The sheet comes from the ufficio di stato civile, the civil registry inside your Comune. In Rome that is the town hall of the district where you are registered, and the clerk prints it from the register that also holds your birth entry. Bring identity and the full name and birth details of the person you are marrying. Foreign registrars often want both names on the sheet.
The state office that stamps it
A civil registry sheet is an administrative paper, so the Prefettura legalises it. That office holds the specimen signatures of the town-hall clerks and stamps on that basis. Embassy legalization of a Certificate of No Impediment in Rome always runs through the Prefettura, never the Procura, which is kept for court and notarial acts.
Closing the chain at the mission
Then the wedding country's embassy or consulate in Italy adds the last seal. Consular legalization of a Certificate of No Impediment in Italy is quick at the counter but slow to book, so take the earliest slot you are offered. Bring your passport, the stamped sheet and whatever form the mission publishes. Several also ask for the wedding date and the venue.
Ask that mission one question before you start: whether it wants this consular chain at all. The answer turns on the destination's own rules, and only the office that will read the sheet can give it. A written reply also tells you whether a lighter, single-step certification is enough. Keep it with your file until the ceremony.
Dates, deadlines and the wedding
Everything about this paper is dated. The registry prints your status as at that morning, and most wedding offices abroad will take only a recent sheet. Embassy attestation of a Certificate of No Impediment in Rome adds 10–15 business days, or 3–5 business days by the express route. Count backwards from the ceremony, then order the sheet.
Cost and the usual snags
The cost is a €16 tax stamp (marca da bollo) plus the mission's consular fee. Snags are nearly always names: a middle name on the passport but not on the sheet, or a partner's surname spelled two ways. Check every spelling letter by letter at the town hall. Get that right and you legalize a Certificate of No Impediment in Rome once, not twice.