Each of these is a refusal this regime lets a counterparty attempt, paired with the answer to it. Reading them before you write is worth more than any amount of polish on the letter itself.
"We are holding it until the Nebenkostenabrechnung"
high likelihoodThe landlord keeps the entire deposit pending the annual operating-cost reconciliation, sometimes for more than a year.
What answers it
A landlord may retain only so much as is needed to secure an identified and quantified expected shortfall, not the whole deposit as a matter of routine. Ask what the expected shortfall is, on what basis it is calculated, and demand release of the balance now.
BGB § 551 — § 551 (Begrenzung und Anlage von Mietsicherheiten)
"You owed cosmetic repairs (Schönheitsreparaturen)"
high likelihoodThe landlord deducts for redecoration under a clause in the lease.
What answers it
German courts have struck down large numbers of these clauses — rigid decoration timetables and obligations imposed on a tenant who took the flat undecorated are typically void, and a void clause supports no deduction at all. Send the exact wording of your clause to a Mieterverein before you concede anything on this ground.
"The property needed cleaning and redecorating"
high likelihoodThe landlord charges for cleaning, carpet wear, scuffed paint or tired fittings and treats the deposit as a refurbishment fund.
What answers it
Fair wear and tear from ordinary use is not a recoverable loss in any of the regimes this product covers — a deduction must reflect damage or a breach beyond ordinary use, must be evidenced, and must be reduced for the age and remaining life of the item. Ask for the invoice, the check-in and check-out evidence, and the calculation.
"Prove you did not cause it"
high likelihoodThe landlord asserts damage and expects the tenant to disprove it, often without a check-in inventory.
What answers it
It is the party seeking to keep the money who must justify keeping it. Where there is no dated check-in record to compare against, an adjudicator has nothing to measure the alleged damage from, and the deduction generally fails on that ground alone.
Deductions raised more than six months after handover
medium likelihoodThe landlord produces a damage claim long after the keys came back.
What answers it
BGB § 548(1) bars the landlord’s claims for damage to the property six months after it is returned. A claim first raised after that is unenforceable, and the deposit must be released.
BGB § 548 — § 548(1) (Verjährung der Ersatzansprüche — six months from return of the property)