What the paper actually says
A certificate of no impediment says one simple thing: no rule of Italian law stops you from marrying. Your Comune builds it from what its own books hold, so your civil status must be up to date there. If you were married before, the record of how that ended must show in the file.
Couples write to ask how to apostille a Certificate of No Impediment weeks after the wedding date is booked. Order it early. If the Comune finds a gap in its books, a divorce not yet noted or a death not yet filed, you will lose time putting that right first.
Who stamps it in Padua
An apostille is a single stamp under the Hague rules, which Italy has followed since 1978. It tells a foreign registrar that the Italian signature on your paper is genuine. Papers from a town hall are administrative, so the Prefettura (Prefecture) in Padua puts the stamp on.
Do not send this one to the Procura della Repubblica. That office, which sits at the court, handles rulings by judges and deeds drawn up by notaries. Your marriage paper is neither. The court route only matters when a judge's order sits behind your file. So if you apostille a Certificate of No Impediment in Italy, check the letterhead first.
The fee and the clock
The apostille cost for a Certificate of No Impediment in Padua is the flat state charge: €16 per document as a tax stamp. Some papers are exempt, and marriage files can be among them, so ask the clerk what applies to yours before you spend.
Timing is the part that bites. This paper speaks about your status on the day it was drawn, so registrars abroad want a recent one and will refuse an old sheet. Ask your venue how new the copy must be, then work backwards: order, stamp, translate, travel.
At the registrar's desk abroad
The registrar who will marry you owns the rulebook. Some want the nulla osta plus a birth record, some want a sworn translation in their language, and some hand you their own form to have signed. Write to them, save what they answer, and shape the file around it.
Most people who apostille a Certificate of No Impediment in Padua pair it with a sworn translation, because a foreign clerk cannot read Italian. Our translator swears the asseverazione, a formal oath that the wording matches, before a Tribunale. Note that legalisation of a Certificate of No Impediment in Padua proves the seal, not your right to marry under local law.