How high may the rental deposit be?
The deposit is at most three times the monthly rent without the operating costs stated as a flat rate or advance payment (§ 551 (1) BGB). So the net cold rent counts, not the warm rent.
A higher agreement is invalid to that extent. The tenant can reclaim the part above the limit (§ 551 (4) BGB).
Maximum deposit = 3 × monthly rent without separately stated operating costs
- Net cold rent with advance payment: 3 × net cold rent.
- Rent with operating cost flat rate: 3 × rent without the flat rate.
- Inclusive rent without separately stated operating costs: 3 × inclusive rent.
- Rent for a parking space or furniture in the same lease is part of the rent. Heating cost advances are operating costs and do not count.
Worked example
The net cold rent is €750, plus €200 operating cost advance. The flat is let from 1 Nov 2026.
- Maximum deposit: 3 × €750 = €2,250. Not 3 × €950 = €2,850.
- Instalments: €750, €750 and €750.
- Instalment 1 at the start of the tenancy on 1 Nov 2026. That is a Sunday, so payment is only due on Monday, 2 Nov 2026 (§ 193 BGB).
- Instalment 2 with the December rent: the 3rd working day is Thursday, 3 Dec 2026.
- Instalment 3 with the January rent: New Year's Day, Saturday and Sunday do not count, the 3rd working day is Wednesday, 6 Jan 2027. In Baden-Württemberg, Bavaria and Saxony-Anhalt, 6 January is a public holiday, so there it is 7 Jan 2027.
Instalments and due dates
The tenant may pay the deposit in three equal monthly instalments (§ 551 (2) BGB). The first is due at the start of the tenancy, the other two together with the immediately following rent payments.
If the lease sets no payment day of its own, rent is due by the 3rd working day of the month (§ 556b (1) BGB). According to the Federal Court of Justice, Saturday does not count as a working day here.
- If the tenancy starts mid-month, instalment 2 is due with the rent for the following month.
- For odd amounts, the last instalment differs by at most 2 cents. CIRO rounds the first instalments up and puts the remainder into the last one.
- More than three instalments are possible if the landlord agrees.
Investment and interest
The landlord must invest the deposit separately from their own assets with a credit institution, at the usual interest rate for savings deposits with a three-month notice period (§ 551 (3) BGB). Other forms of investment are possible by agreement.
The interest belongs to the tenant and increases the deposit. Under “More assumptions” you can enter the interest rate and the investment period.
Repayment after moving out
There is no fixed statutory deadline for repayment. The landlord may take a reasonable time to check whether they still have claims. Courts usually allow a few months for this. For a still outstanding service charge statement, the landlord may withhold a reasonable part for longer.
The often-quoted 6 months come from the limitation period: claims for changes or deterioration of the flat become time-barred 6 months after it is returned (§ 548 (1) BGB). That is not a repayment deadline.
Common mistakes
- Deposit calculated from the warm rent instead of the rent without operating costs.
- Full deposit requested in one payment although the tenant may pay in instalments.
- Deposit and guarantee requested on top of each other: several securities generally count together against the limit.
- Deposit kept in the landlord's own account instead of invested separately.
- More deposit expected after a rent increase: the deposit does not rise automatically.