Short answer
The Quran speaks about riba in four places: 30:39, 4:161, 3:130 and 2:275 to 2:280. Many commentators read them as a step-by-step prohibition that ends in Surah al-Baqarah, where Allah forbids interest outright, warns of war from Allah and His Messenger, and lets the lender keep only his principal.
Riba is haram by definitive text of the Quran (2:275 to 2:279), and its prohibition is agreed. The hadith add the rules of riba in exchanges of gold, silver and staple foods (riba al-fadl) to the riba of loans.
The four schools agree on this.
Explanation
Here are the Quran's passages on riba, in the order many commentators believe they came:
- 30:39 (Makkah). Riba "will not increase with Allah", while zakat given for Allah's sake is multiplied. A moral warning, before any legal ruling.
- 4:161. Among the sins of some of the earlier people was "their taking of usury while they had been forbidden from it". Riba was forbidden in earlier revelation too.
- 3:130. "Do not consume usury, doubled and multiplied." The first direct command to Muslims, aimed at the compounding interest of the time.
- 2:275 to 2:280. The final ruling: "Allah has permitted trade and has forbidden interest." Allah destroys interest and grows charity (2:276). Believers must give up what remains of it (2:278), or face war from Allah and His Messenger, and keep only their principal (2:279). A debtor in hardship should be given time (2:280).
The hadith fill in the detail. The Prophet ﷺ cursed the one who takes riba, the one who pays it, the one who writes it and its witnesses. He also set the rule for exchanges: gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates and salt for salt must be equal and hand to hand, and whoever gives or asks for more has dealt in riba. This is why exchanging old gold for less new gold is a problem; see Can you exchange old gold for new gold?
For why riba is forbidden, see Why is interest haram?, and for its types, What is riba in Islam?
The evidence
Quran, Surah Ar-Room 30:39
وَمَآ ءَاتَيْتُم مِّن رِّبًۭا لِّيَرْبُوَا۟ فِىٓ أَمْوَٰلِ ٱلنَّاسِ فَلَا يَرْبُوا۟ عِندَ ٱللَّهِ ۖ وَمَآ ءَاتَيْتُم مِّن زَكَوٰةٍۢ تُرِيدُونَ وَجْهَ ٱللَّهِ فَأُو۟لَٰٓئِكَ هُمُ ٱلْمُضْعِفُونَ ﴿٣٩﴾
And whatever you give for interest to increase within the wealth of people will not increase with Allah. But what you give in zakah, desiring the countenance of Allah - those are the multipliers.
The earliest passage contrasts riba with zakat.
Quran, Surah An-Nisaa 4:161
وَأَخْذِهِمُ ٱلرِّبَوٰا۟ وَقَدْ نُهُوا۟ عَنْهُ وَأَكْلِهِمْ أَمْوَٰلَ ٱلنَّاسِ بِٱلْبَٰطِلِ ۚ وَأَعْتَدْنَا لِلْكَٰفِرِينَ مِنْهُمْ عَذَابًا أَلِيمًۭا ﴿١٦١﴾
And [for] their taking of usury while they had been forbidden from it, and their consuming of the people's wealth unjustly. And we have prepared for the disbelievers among them a painful punishment.
Riba was forbidden to earlier communities as well.
Quran, Surah Al-Baqara 2:276
يَمْحَقُ ٱللَّهُ ٱلرِّبَوٰا۟ وَيُرْبِى ٱلصَّدَقَٰتِ ۗ وَٱللَّهُ لَا يُحِبُّ كُلَّ كَفَّارٍ أَثِيمٍ ﴿٢٧٦﴾
Allah destroys interest and gives increase for charities. And Allah does not like every sinning disbeliever.
Riba loses its blessing while charity grows.
Quran, Surah Al-Baqara 2:280
وَإِن كَانَ ذُو عُسْرَةٍۢ فَنَظِرَةٌ إِلَىٰ مَيْسَرَةٍۢ ۚ وَأَن تَصَدَّقُوا۟ خَيْرٌۭ لَّكُمْ ۖ إِن كُنتُمْ تَعْلَمُونَ ﴿٢٨٠﴾
And if someone is in hardship, then [let there be] postponement until [a time of] ease. But if you give [from your right as] charity, then it is better for you, if you only knew.
The final passage tells creditors to give struggling debtors time instead of charging more.
Sahih Muslim 1587
Sahih... الذهب بالذهب والفضة بالفضة والبر بالبر ...
"Gold for gold, silver for silver, wheat for wheat."
Begins the list of items that must be exchanged equally and hand to hand.
Sahih Muslim 1584
Sahih... فمن زاد أو استزاد فقد أربى ...
"Whoever gives more or asks for more has dealt in riba."
Defines riba in exchanges of the same kind.
Where the ruling is recorded
- Ahkam al-Quran (al-Jassas), Commentary on Surah al-Baqarah, the verses on riba. The Hanafi reading of the riba verses and what they forbid.
- al-Hidaya, Kitab al-Buyu', Bab al-Riba. The Hanafi rules of riba in loans and exchanges.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. 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.