Embassy legalisation for use in Vietnam
Consular attestation is required here, and there is no shorter path around it. The route has three points: the paper is notarised or certified where that applies, an Italian authority legalizes the signature, and the destination's mission in Italy attests what Italy has done. Document legalization for Vietnam is finished only when the third mark is on the file.
Which Italian desk signs first
The choice is made by whoever signed your paper, not by what the paper is about. A birth entry, a residence certificate or a school record carries the signature of a public official, so it goes to the Prefettura. A notarial deed, a power of attorney or a court judgment goes to the Procura della Repubblica. Sending a file to the wrong one wastes the whole leg, because the desk simply hands it back unmarked.
The consular stage for Vietnam
Once Italy has signed off, the file moves to the Vietnamese embassy or consulate in Italy. This is where an embassy attestation for Vietnam is actually produced: the mission checks the Italian mark against what it expects to see and adds its own, along with a fee it sets. Nothing about the content of your paper is judged at this point — the mission is confirming Italian paperwork, not reading your story.
Cost and timing for this route
Budget for one fixed charge and one that is not fixed: the €16 tax stamp on the Italian side, and the mission's own fee on the other. For time, the standard window is 10–15 business days and the express one is 3–5. Consular legalization for Vietnam takes up most of that span, so the sensible plan is to have the Italian mark ready early and let the mission have the slack.
Building the bundle in the right order
Every mark on the file covers only what was already there when it went on. So a translation, if your file needs one, belongs inside the bundle before the Italian desk sees it, sworn in front of a Tribunale with the asseverazione, the signed statement of accuracy, attached. Adding a page after the consular stage leaves it outside the chain, and the whole run starts again from the first desk in Padua. Handled as one job, an embassy legalization for Vietnam from Padua clears both desks in a single pass.