Kaution Rules: How Much Your Landlord Can Ask For, and When You Get It Back

The Kaution rules that matter most to you as a tenant split into two separate questions: how much can be demanded upfront, and how long your landlord can legally hold onto it after you move out. The first is tightly regulated; the second is murkier than most tenants expect.

On the amount: §551 BGB caps a residential deposit at three months' cold rent (Kaltmiete, excluding Nebenkosten), and you have the legal right to spread payment across three equal monthly installments rather than paying it all upfront — the first due when you move in, the next two with your following two rent payments. A landlord can offer a lower deposit or waive it, but can't legally demand more than the cap.

Your deposit has to be kept separately from the landlord's own money, in an account that earns interest at the standard rate for savings deposits, and that interest belongs to you, not the landlord (§551 Abs. 3 BGB) — it should be added to what you get back, not quietly kept.

On the return timeline: there's no fixed statutory deadline, which is the part that catches people out. The Bundesgerichtshof (Federal Court of Justice) has set the practical standard instead — landlords get a "reasonable inspection period," generally interpreted as up to six months to check for damage and settle outstanding claims, extending to as long as twelve months if a Nebenkostenabrechnung is still pending. That's not a hard legal deadline so much as a benchmark courts use when a dispute actually gets litigated.

Legitimate deductions cover unpaid rent, actual damage beyond normal wear and tear (a landlord can't charge you for reasonably faded paint or worn carpet from ordinary use), and unpaid Nebenkosten once the final bill is settled. What a landlord can't do is hold your entire deposit indefinitely "just in case," or deduct for repairs that were already due regardless of your tenancy.

If your deposit doesn't show up within a reasonable window and you haven't heard a clear reason why, put a written request in with a deadline attached before escalating — and if that doesn't work, a Mieterverein or, as a last resort, small-claims court (which doesn't require a lawyer for amounts under €5,000) are the standard next steps.