The German operating-cost statement (Betriebskostenabrechnung), explained

If you manage residential property in Germany, the Betriebskostenabrechnung (the annual operating-cost statement) is one of the documents you cannot get wrong. It is governed by statute, it has a hard deadline, and tenants have clear rights to challenge it.

What it is

Tenants typically pay an advance (Vorauszahlung) on operating costs each month. Once a year the landlord must reconcile those advances against the actual costs and issue a statement showing the difference, refunding an overpayment or billing a shortfall.

Which costs can be passed on

Only costs that are "umlagefähig" (apportionable) under the Betriebskostenverordnung (BetrKV) may be included, and only if the lease actually provides for them. Property tax, water, heating, lift, building cleaning, and similar recurring costs generally qualify; one-off repairs and administration costs generally do not.

The twelve-month deadline (§556 BGB)

The statement must reach the tenant within twelve months of the end of the accounting period. Miss it, and the landlord generally loses the right to bill any shortfall, though a refund still has to be paid. The deadline is the single most common and most expensive mistake.

Why this is hard across a portfolio

Doing one statement is manageable. Doing hundreds, each with the correct apportionment key, the right cost categories, and the deadline tracked per unit, is where it becomes a real operational risk. This is exactly the kind of jurisdiction-specific work Cuvanti builds into the platform rather than leaving to a spreadsheet.

Note: this is general information, not legal advice. Confirm the apportionment and deadlines for your specific leases with a qualified adviser.