Nebenkostenabrechnung: A Landlord's Guide for Germany (2026)
Updated 6/13/2026 · HausMaus Redaktion
As a landlord you must serve the Nebenkostenabrechnung (annual operating-cost statement) within 12 months of the end of the accounting period (§ 556 (3) BGB). It must clearly show the umlagefähige (apportionable) costs, the Umlageschlüssel (allocation key), the advance payments made, and the result — a Nachzahlung (back-payment) or a Guthaben (credit). Miss the deadline and you can no longer demand a back-payment.
What is the Nebenkostenabrechnung?
The Nebenkostenabrechnung (correctly: Betriebskostenabrechnung, the annual operating-cost statement) is the yearly reconciliation in which you, as landlord, set the actual Betriebskosten (operating costs) against your tenant's advance payments. The result is either a Nachzahlung (back-payment, costs higher than the advances) or a Guthaben (credit).
The 12-month deadline (§ 556 BGB)
You must serve the statement on the tenant no later than 12 months after the end of the accounting period. For a calendar-year period that means: the statement for 2025 must reach the tenant by 31 December 2026 at the latest.
Important: Miss this deadline and you lose the right to a Nachzahlung. A tenant's Guthaben, by contrast, remains owed.
Step by step
- Set the accounting period — usually 12 months, typically the calendar year.
- Collect the umlagefähige (apportionable) costs — only Betriebskosten under § 2 BetrKV (see below).
- Apply the Umlageschlüssel (allocation key) — the default is living area; heating/hot water by consumption (HeizkostenV).
- Deduct the advance payments — the monthly Vorauszahlungen the tenant made.
- Show the result — Nachzahlung or Guthaben, with a payment deadline.
- Serve it on time — provably (e.g. by Einwurf-Einschreiben, registered delivery).
Umlagefähig vs. nicht umlagefähig
Apportionable (§ 2 BetrKV): Grundsteuer (property tax), water/sewage, heating, refuse collection, building cleaning, garden upkeep, communal electricity, lift, Hausmeister (caretaker), insurance.
Not apportionable: administration costs, maintenance and repairs, bank/account fees, reserves (Rücklagen).
Common mistakes that void the statement
- Missing or unclear Umlageschlüssel
- Non-apportionable costs billed by mistake
- Deadline missed
- Advance payments deducted incorrectly or not at all
Check it quickly
Unsure whether your statement is on time and which items are apportionable? Use the free Nebenkosten-Checker below — it checks the 12-month deadline and the individual cost types in seconds.
With HausMaus it's automatic
HausMaus collects receipts across the year, assigns them to the umlagefähige cost types, applies the correct Umlageschlüssel, and produces a legally sound, on-time Nebenkostenabrechnung as a PDF — for a single apartment or the whole portfolio.
1. Check the deadline (§ 556 (3) BGB)
The statement must reach the tenant no later than 12 months after the end of the accounting period. After that, the landlord can no longer demand a Nachzahlung (back-payment).
Please choose the accounting year and the received date.
2. Check the cost items (§ 2 BetrKV)
Select the items from your statement. We show what is umlagefähig (apportionable) — and what the landlord must bear.
Tap the items that appear on your statement.
This calculator gives initial guidance and is not a substitute for legal advice.
Frequently asked questions
By when must the Nebenkostenabrechnung reach the tenant?
At the latest 12 months after the end of the accounting period (§ 556 (3) BGB). For a calendar-year period that is 31 December of the following year. After that you can no longer demand a Nachzahlung (back-payment) — but a tenant's Guthaben (credit) still stands.
Which costs are umlagefähig (apportionable)?
Only operating costs (Betriebskosten) under § 2 BetrKV — e.g. Grundsteuer (property tax), water, heating, refuse collection, building cleaning, garden upkeep, communal electricity and insurance. Administration and maintenance/repair costs are NOT apportionable.
Which Umlageschlüssel (allocation key) is correct?
Unless the Mietvertrag (tenancy agreement) says otherwise, costs are allocated by living area (§ 556a BGB). Heating and hot-water costs must be billed 50–70% by consumption (HeizkostenV).
What happens if the statement contains errors?
Formal errors (e.g. a missing Umlageschlüssel) make the statement invalid. Substantive errors may be corrected within the 12-month deadline; after it, only in the tenant's favour.
Sources
This guide is based on the statute text and official sources. You can read the cited paragraphs in the original here: