The Italian paper behind the English name
A certificate of no impediment says nothing stands in the way of your marriage. In Italy the near match is the free status record, the certificato di stato libero, held by the town hall. So how to apostille a Certificate of No Impediment starts with asking the registrar abroad which wording they will take.
Get that ask in writing. Registrars set their own wording, and some hand you a form they want filled in. Others want the free status record plus a birth record, or proof that a past marriage has ended. Knowing the list up front saves you a second run through every office.
Counter first, then the stamp
To apostille a Certificate of No Impediment in Italy you first need the record itself, signed and sealed at the counter. Ask the Ufficio di Stato Civile in Naples, the office that keeps your entry, and take your ID with you. An apostille is the slip the state adds to show the clerk's hand is real.
You apostille a Certificate of No Impediment in Naples at the Prefettura (Prefecture), the state's local office, since a civil record counts as administrative. If a court ended your last marriage, that decree is a judicial paper, so it goes to the Procura della Repubblica at the court. Two papers can mean two desks.
Match the names letter for letter. The record must read as your passport does, or the registrar abroad will halt the wedding file. Watch for a middle name left out, an accent dropped, or a married surname from a past union. Ask the clerk to mend the entry before any stamp is bought.
Fee, and working back from the date
The apostille cost for a Certificate of No Impediment in Naples is a €16 tax stamp per document, and some papers are exempt. Say what the record is for, because that is what the clerk weighs. No wait is fixed here. These records date quickly, so fix the wedding day first and count backwards.
Who asks to see it
Couples need this page to book a wedding abroad. A town hall, a church or a court overseas may each ask for it before they will set a date. A visa desk may want it with a spouse file. Some countries ask again if the wedding slips by a season, so keep the wording they gave you.
Translation and acceptance notes
Wedding packs abroad may still list the legalisation of a Certificate of No Impediment in Naples. Inside the Hague group the apostille answers that. For another EU state, ask first, because EU rules can drop the stamp for civil records. Beyond both, a consulate may still have to sign.
Most registrars want the text in their own language. The facts here name none, so write and ask which one. A sworn version is signed in front of a Tribunale (court), where the translator swears the asseverazione, a formal oath that the words match. Ask whether they want that oath stitched to the stamped record.