One of the main conditions of marriage to be legal is “supervision”, which means that the marriage should be with the presence of an authority. This authority should be someone that can protect the rights of the woman when needed. This is called Wali.
If this is the first marriage of the woman, the presence (or information) of woman’s father is required at first. If he doesn’t approve the marriage, then the woman and the man can apply to the authorities for being married. In addition, the man and the woman should talk and agree on the Mahr, whether it will be paid right away or counted as debt. If it will be debt, it will have to be written within the presence of the Wali and the witnesses. The Wali should ask about these issues to the couple and remind them of their rights and responsibilities. Marriage is a serious issue. It cannot be done secretly. It should be announced to the kith and kin. The couples should be very well aware of their responsibilities.
Only after these procedures, a couple can start living together as husband and wife.