Allah says: divorce is twice, then either keep her with kindness or release her with good treatment (2:229). Divorce is allowed but disliked, and a last resort. It should be given once, in a state of purity, without intercourse in that period, and then the waiting period (iddah) follows (65:1). A woman may also seek a khul', as the wife of Thabit ibn Qays did in the time of the Prophet ﷺ.
1The way of the Sunnah
A single divorce in a period of purity, without intercourse, then waiting until the end of the iddah.
During the iddah the husband may take her back, and the wife stays in the home (65:1).
After the iddah ends the divorce is final, and they can marry again by a new contract.
A third divorce makes her unlawful for him until she marries another man in a real marriage (2:230).
2The waiting period (iddah)
Three periods for a woman who still has her cycle (2:228).
Three months for those who no longer menstruate or have not yet begun (65:4).
Until delivery for a pregnant woman.
Four months and ten days for a widow (2:234).
3Khul'
When the wife dislikes the marriage and fears she cannot fulfil her duties, she may return what she was given and the marriage is ended.
The Prophet ﷺ told Thabit ibn Qays to accept the garden and divorce her. It ends the marriage with one divorce.
Where the schools differ
The four Sunni schools agree on the main ruling above and differ in these points. No school is preferred here.
Three divorces in one word. the majority of the schools count them as three, and some scholars (like Ibn Taymiyyah) hold it counts as one. Ask a scholar.
Khul'. the Hanafi, Maliki and Shafi'i schools count it as a final divorce. The Hanbali school, in the well-known narration, treats it as an annulment (faskh) and not a divorce, with a waiting period of one cycle.
Note
Divorce has important legal effects. Ask a qualified scholar and follow the law of your country for the legal side.
Die (widerrufliche) Scheidung ist zweimal (erlaubt). Dann (sollen die Frauen) in rechtlicher Weise behalten oder in ordentlicher Weise freigegeben (werden). Und es ist euch nicht erlaubt, etwas von dem, was ihr ihnen gegeben habt, (wieder) zu nehmen, außer wenn die beiden fürchten, daß sie Allahs Grenzen nicht einhalten werden. Wenn ihr aber befürchtet, daß die beiden Allahs Grenzen nicht einhalten werden, dann ist für die beiden keine Sünde in dem, womit (an Geld) sie sich löst. Dies sind Allahs Grenzen, so übertretet sie nicht! Wer aber Allahs Grenzen übertritt, diejenigen sind die Ungerechten.
O Prophet, wenn ihr euch von Frauen scheidet, dann scheidet euch von ihnen auf ihre Wartezeit hin, und berechnet die Wartezeit. Und fürchtet Allah, euren Herrn. Weist sie nicht aus ihren Häusern aus; sie sollen auch nicht selbst ausziehen, außer, sie begehen etwas klar Abscheuliches. Dies sind Allahs Grenzen
Geschiedene Frauen sollen (mit sich) selbst drei Zeitabschnitte abwarten. Und es ist ihnen nicht erlaubt, zu verheimlichen, was Allah in ihrem Mutterleib erschaffen hat, wenn sie an Allah und den Jüngsten Tag glauben. Und ihre Ehemänner haben ein größeres Anrecht, sie zurückzunehmen, wenn sie eine Aussöhnung wollen. Und ihnen (den Frauen) steht in rechtlicher Weise (gegenüber den Männern) das gleiche zu, wie (den Männern) gegenüber ihnen. Doch die Männer haben ihnen gegenüber einen gewissen Vorzug. Und Allah ist Allmächtig und Allweise.
From the Sunnah
Sahih al-Bukhari 5273Authentic collection
The point of the hadith: The wife of Thabit ibn Qays came to the Prophet ﷺ because she disliked staying married. He had her return the garden she was given, and told Thabit to accept it and divorce her.
Read the Arabic text
حَدَّثَنَا أَزْهَرُ بْنُ جَمِيلٍ، حَدَّثَنَا عَبْدُ الْوَهَّابِ الثَّقَفِيُّ، حَدَّثَنَا خَالِدٌ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ،. أَنَّ امْرَأَةَ، ثَابِتِ بْنِ قَيْسٍ أَتَتِ النَّبِيَّ صلى الله عليه وسلم فَقَالَتْ يَا رَسُولَ اللَّهِ ثَابِتُ بْنُ قَيْسٍ مَا أَعْتُبُ عَلَيْهِ فِي خُلُقٍ وَلاَ دِينٍ، وَلَكِنِّي أَكْرَهُ الْكُفْرَ فِي الإِسْلاَمِ. فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَتَرُدِّينَ عَلَيْهِ حَدِيقَتَهُ ". قَالَتْ نَعَمْ. قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " اقْبَلِ الْحَدِيقَةَ وَطَلِّقْهَا تَطْلِيقَةً ". قَالَ أَبُو عَبْد اللَّهِ لَا يُتَابَعُ فِيهِ عَنْ ابْنِ عَبَّاسٍ
This is general information, not a fatwa. For your own situation, ask a qualified scholar.
Fiqh questions
Divorce and khul'
Allah says: divorce is twice, then either keep her with kindness or release her with good treatment (2:229). Divorce is allowed but disliked, and a last resort. It should be given once, in a state of purity, without intercourse in that period, and then the waiting period (iddah) follows (65:1). A woman may also seek a khul', as the wife of Thabit ibn Qays did in the time of the Prophet ﷺ.
Is this a fatwa?
No. It is a summary of well-known rulings with their evidence. For your own case, ask a qualified scholar.
What if my school differs from this answer?
Follow the view of the school you follow and the scholar who teaches you. The page lists the differences of the four schools.