What is nikah siri in Indonesia and can it be validated later?

Nikah siri is a marriage that is not recorded by the Office of Religious Affairs (KUA). Article 2 of the UU Perkawinan states that a marriage is valid when performed according to religious law, and every marriage is recorded according to statutory regulations. Without recording, the wife and children have no official proof and find it hard to claim maintenance, jointly acquired property and inheritance. The remedy is an application for itsbat nikah (marriage validation) at the Religious Court, but it is not a shortcut to avoid the conditions for polygyny. For a husband who is already married, an unrecorded marriage usually means bypassing the required court permission. Unrecorded polygyny also does not appear in official statistics. This site does not encourage unregistered marriages. See Indonesia.