Search for the conditions of marriage in Islam and you will find everything: five-point lists, seven-point lists, pillars mixed up with conditions, cultural customs presented as obligations. The safest path is to go back to what the scholars answered when they were actually asked. Every statement in this article rests on a fatwa of Shaykh Abd al-Aziz Ibn Baz, quoted with its link.
The contract brings together four people
This is the foundation. Asked about a marriage contract concluded without a guardian, Shaykh Ibn Baz answers:
"Marriage brings together four people: the wali, the husband and the two witnesses. That is the legislated marriage."
The woman is not among the four because she is not the one who concludes: her wali gives her in marriage. The same fatwa describes the act itself: the wali says "I have given you So-and-so, daughter of So-and-so, in marriage", the husband answers "I accept", and the two witnesses bear witness to it.
The wali is the woman's closest male relative on the paternal side: her father first, then, failing him, the grandfather, the son, the full brother, the paternal half-brother, then the rest of the agnates, from closest to furthest, still according to fatwa no. 12666. We devote a separate article to the role of the wali.
The woman's consent
The wali concludes the contract, but he does not decide in place of the woman in his care. Shaykh Ibn Baz is categorical:
"It is not permitted for anyone to compel his daughter, whether she has been married before or is a virgin. It is incumbent on him, on the contrary, to ask for their permission and to consult them about themselves."
The same fatwa recalls the hadith of the two Sahihs: the virgin is not married before her permission is sought, and her permission may be her silence. The wali and consent are therefore not opposed: they are two requirements of one and the same contract. See also consent and forced marriage.
The offer, the acceptance, and nothing else made obligatory
Asked about the wording of the contract, the Shaykh describes it this way:
"And if he says: I have given her to you in marriage, and the other says: I accept, without delivering a khutbah or anything else, there is no harm in it, as long as the conditions are met: that both spouses be free of impediments, with the consent of both spouses, the presence of two witnesses, and that it come from the woman's wali, who is the closest of her agnates."
The khutbah of the nikah, the one that opens with the praise of Allah, is preferable but is not a condition: whoever does not deliver it commits no fault, the same fatwa specifies.
The dowry: indispensable, without being a condition
This is the nuance that most lists flatten. Asked about the status of the mahr, Shaykh Ibn Baz answers:
"The dowry is not one of its pillars, nor one of its conditions, but it is indispensable."
And he draws the consequence in the same answer: if the contract is concluded without a named dowry, the marriage is valid, and the dowry of her likes is then owed to the wife. The dowry is a right that cannot be negotiated down to nothing, but its absence from the contract does not void it. On its amount, see the dowry in Islam.
The announcement: what separates marriage from secrecy
"Making the marriage public is obligatory, so that it be distinguished and not be fornication; making it public and announcing it by giving a walimah."
The same fatwa warns against the opposite excess: one should not overburden oneself, because overburdening keeps people from marrying. The announcement is owed, lavishness is not. A contract kept hidden raises a problem of another kind, treated in secret marriage in Islam.
What voids the contract, and how it is remedied
What of a marriage concluded without a wali, where the woman marries herself off? Shaykh Ibn Baz answers that this is not permitted, and that it is void according to the majority of the people of knowledge (fatwa no. 12666 quoted above).
For a contract concluded through negligence, without a wali or without witnesses, he points to the remedy:
"As for what was done through negligence, it should be renewed: let the marriage be done again with its legislated conditions, with a wali and two witnesses present at the new contract; and their children born beforehand are attributed to them by reason of the doubt."
No imposed place, no imposed moment
None of the conditions above concerns the venue or the date. Asked about when the contract is written, the Shaykh answers that the contract is permitted at any moment, even long before the wedding, and that it can be concluded at the madhun's, at the judge's, or in any place, in the presence of two upright witnesses (fatwa no. 15986, binbaz.org.sa).
How Nikah translates these conditions
The platform is built around what these fatwas describe. A sister enters her wali at sign-up, and he can follow the exchange from the first message. Every message is read by human moderation before delivery. One exchange at a time, no photos, and a mouqabalah held in the guardian's presence.
The full list of conditions, with the Arabic text of each fatwa, is on the page What makes a nikah valid.