Nulla Osta is an Italian terms of the Non-Impediment Letter, a certificate certify that you are legally free to marry and there is no objection to your proposed marriage.
Registering a Marriage in Italy
If you are registering your marriage in Italy, you need to get a Certificate of Singlehood from your local Civil Registry Office in Indonesia. The certificate must be legalized by the Ministry of Law and Human Rights (so called â€œMinistry of Justiceâ€), and the legalized by the Foreign Affairs Ministry, and lastly by the Italian Embassy in Jakarta. Thereafter, you need to make an exchange for a Nulla Osta at the nearest Indonesian Consulate to where you are getting married in Italy.
You must not set-up a marriage date before you can get complete and legalize singlehood certificate. There are too many surprises down the line. You need to work with government institutions and bureaucracy that sometime delays the time. Not to mention ridiculous supporting documents that you must supply before hand. You need to allow a month or two before you finally set the date and register the marriage in Italy.
Embassy of Indonesia
You need also to consult the Indonesian Embassy in Rome before initiating any actions. Sometime they only require legalizations with Ministry of Justice and Foreign Ministry. You are not required to secure Italian Embassy legalization or even Italian translation of your singlehood certificate.
Collect More Information
Most important of all, you need to collect more information from the very beginning. Securing lots information can sometime put you in the in right track. Information sometime can be very expensive, and access to it cannot be verified instantly. Therefore, you may ask an expert or local Indonesian lawyer to consult about the issues.
Good luck with your marriage!