Indonesian law states that a couple must share the same religion to get married. For marriage purposes, there are five religions legally recognised in Indonesia:
A foreigner must practise one of these faiths, or a legal marriage cannot take place. For Indonesians, religious affiliation is part of social and legal identity and every Indonesian citizen must claim one of five religions. By the age of 17, Indonesian citizens must have their religious faith confirmed as indicated on their National Identification Card (Kartu Tanda Penduduk or KTP).
Indonesians may not be agnostic or atheist, and nor may a foreigner who wants to marry an Indonesian. If a foreigner and an Indonesian do not share the same religion, the only practical alternative is for one of the two to convert to the other’s faith. If conversion is necessary, the foreigner is obliged to convert as it is rare that an Indonesian family will support the religious conversion of a family member, especially if the couple remains in Indonesia after marriage.
All marriages should be registered with the state, but as marriage is also seen as a religious act, it must be performed within the context of a legitimate religious ceremony.
Religious conversion varies from region to region and it is best to consult local marriage authorities. For example, a foreigner can convert and marry in the same week, or even on the same day. This must be arranged with the presiding priest, pastor, or imam.
Once converted, a certificate will be presented to the spouse who has converted, and that in turn can be presented as proof to the Civil Registry (Kantor Catatan Sipil) and an Office of Religious Affairs (Kantor Urusan Agama).
For conversions to Islam, it is not uncommon for the conversion to take place in a mosque, immediately followed by the marriage ceremony. Two official witnesses must be present, and they sign a certificate verifying “entrance” into the Muslim religion.