Short answer
A Muslim man may have up to four wives at once if he can treat them justly: equal nights, separate housing and fair provision, and if he can afford to support them. If he fears he will be unjust, one wife is the command. In Shariah the first wife's permission is not a condition of validity, but the law of the land and her rights must be considered.
Marrying up to four is permissible (mubah) for one who can provide for each and be just between them. Justice in nights, housing, food and clothing is wajib; equal love is not required. If he fears injustice, marrying more than one is not permissible for him. The first wife's consent is not a condition for the second nikah.
Other madhhabs
- Hanbali
- If the wife stipulated in the nikah that he will not marry another, the condition is binding; if he does, she has the right to end the marriage.
Explanation
Allah allows marriage to "two or three or four", then says, "But if you fear that you will not be just, then marry only one" (4:3). So the permission is tied to justice. Allah also says husbands will never be able to be perfectly equal in their feelings, but must not lean so far towards one that the other is left "hanging" (4:129). The Prophet ﷺ warned that a man who favours one wife will come on the Day of Resurrection with one side of his body leaning.
The conditions and duties:
- Ability to support each wife in food, clothing and housing.
- Separate housing: each wife has the right to her own private quarters. Co-wives cannot be made to share one home without their agreement.
- Equal turns: nights are divided equally. Travel with one wife is fair if decided by lot, as the Prophet ﷺ did.
- No more than four at one time, and not two sisters, or a woman and her aunt, together.
- Justice in outward things, not in love, which no one controls.
Is the first wife's permission needed? Not for the nikah to be valid. But hiding a second marriage, neglecting the first family or causing serious harm is sinful. A wife can ask for protection in the nikah contract itself, for example by being given the right to divorce herself (tafwid al-talaq) if he marries again. In the US, UK, Canada and many other countries a second marriage is not legally recognised and can be a crime, and the second wife may have no legal protection. Scholars advise Muslims to keep the law of the land and not to put a wife in a vulnerable position. Seek advice before taking this step. See secret nikah.
The evidence
Quran, Surah An-Nisaa 4:3
وَإِنْ خِفْتُمْ أَلَّا تُقْسِطُوا۟ فِى ٱلْيَتَٰمَىٰ فَٱنكِحُوا۟ مَا طَابَ لَكُم مِّنَ ٱلنِّسَآءِ مَثْنَىٰ وَثُلَٰثَ وَرُبَٰعَ ۖ فَإِنْ خِفْتُمْ أَلَّا تَعْدِلُوا۟ فَوَٰحِدَةً أَوْ مَا مَلَكَتْ أَيْمَٰنُكُمْ ۚ ذَٰلِكَ أَدْنَىٰٓ أَلَّا تَعُولُوا۟ ﴿٣﴾
And if you fear that you will not deal justly with the orphan girls, then marry those that please you of [other] women, two or three or four. But if you fear that you will not be just, then [marry only] one or those your right hand possesses. That is more suitable that you may not incline [to injustice].
Up to four wives are allowed only with justice.
Quran, Surah An-Nisaa 4:129
وَلَن تَسْتَطِيعُوٓا۟ أَن تَعْدِلُوا۟ بَيْنَ ٱلنِّسَآءِ وَلَوْ حَرَصْتُمْ ۖ فَلَا تَمِيلُوا۟ كُلَّ ٱلْمَيْلِ فَتَذَرُوهَا كَٱلْمُعَلَّقَةِ ۚ وَإِن تُصْلِحُوا۟ وَتَتَّقُوا۟ فَإِنَّ ٱللَّهَ كَانَ غَفُورًۭا رَّحِيمًۭا ﴿١٢٩﴾
And you will never be able to be equal [in feeling] between wives, even if you should strive [to do so]. So do not incline completely [toward one] and leave another hanging. And if you amend [your affairs] and fear Allah - then indeed, Allah is ever Forgiving and Merciful.
Outward justice is required even though feelings cannot be equal.
Sunan Abi Dawud 2133
Graded sahih... من كانت له امرأتان فمال إلى إحداهما جاء يوم القيامة وشقه مائل ...
"Whoever has two wives and inclines towards one of them will come on the Day of Resurrection with one side of his body leaning."
Injustice between wives is a serious sin.
Sahih Muslim 1408
Sahih... لا تنكح المرأة على عمتها ولا على خالتها ...
"A woman is not to be married alongside her paternal aunt or her maternal aunt."
Some women cannot be co-wives together.
Where the ruling is recorded
- al-Hidaya, Kitab al-Nikah, Bab al-Qasm. Equal division of nights between wives is wajib.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Nikah, Fasl fi al-Muharramat and Bab al-Qasm. The limit of four, and justice in nights and spending, not in love.
- Kashshaf al-Qina', Kitab al-Nikah, Bab al-Shurut fi al-Nikah. The Hanbali rule that a condition of no second wife binds the husband.
This answer is pending review by the scholars on our team. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.