The 5 Most Common Errors in Nebenkostenabrechnungen

1. Non-allocable Costs Charged

The most common error: the landlord charges costs that may not be passed on to tenants. Under § 2 of the Betriebskostenverordnung (BetrKV), there are exactly 17 allocable cost types. Anything else should not appear in your bill.

Typical examples of non-allocable costs:

• Administrative costs — property management, bookkeeping, account management
• Maintenance and repairs — defective heating, broken pipes, facade renovation
• Vacancy costs — empty apartments may not be passed on to other tenants
• Landlord bank fees

Tip: It is worth checking every individual item in the bill. Comparing the listed cost types with the list in § 2 BetrKV quickly shows: what is not listed there does not belong in the bill.

2. Wrong Allocation Key

Operating costs must be distributed among tenants using a comprehensible key. The most common key is living space. But number of people, consumption, or residential units may also have been agreed.

Common allocation errors:

• A different key is used than the one agreed in the lease
• The total area is incorrect — your share is calculated too high
• Heating costs are not billed by consumption (at least 50% must be consumption-based)
• Commercial areas in the building are not billed separately even though they cause higher costs

Tip: Comparing the allocation key used in the bill with the lease can be worthwhile. If it differs, the bill may be open to objection.

3. Formal Defects — Deadlines and Required Information

A Nebenkostenabrechnung must meet certain formal requirements. If these are missing, the entire bill may be formally ineffective — regardless of whether the figures are correct.

Required information in a correct bill:

• Billing period (maximum 12 months)
• List of total costs by cost type
• Statement of the allocation key
• Calculation of the tenant's share
• Deduction of advance payments already made

In addition, the bill must be delivered no later than 12 months after the end of the billing period. If it arrives late, you generally do not have to pay an additional amount (§ 556 para. 3 BGB) — unless the landlord is not responsible for the delay.

Tip: The date of receipt and the billed period matter. Bills that arrive after the 12-month deadline are late.

4. Heating Costs Not Billed by Consumption

The Heizkostenverordnung (HeizkostenV) requires at least 50% and at most 70% of heating costs to be billed based on consumption. The rest is distributed by living space.

Typical errors:

• Heating costs are allocated entirely by area (without a consumption share)
• Hot-water costs are not shown separately
• The consumption share is below 50% or above 70%
• Ancillary heating costs (maintenance, chimney sweep) are assigned incorrectly

If the Heizkostenverordnung is violated, tenants have the right to reduce their share of heating costs by 15% (§ 12 HeizkostenV).

Tip: A close look at the heating-cost block of the bill can be worthwhile. If no consumption share is shown, the bill is likely to contain an error.

5. Property Tax Allocated Incorrectly

Property tax (Grundsteuer) is one of the 17 allocable operating cost types — but it is often calculated incorrectly. Since the 2025 property tax reform, new assessment bases apply, and many landlords have not yet implemented them correctly.

Common errors:

• The full property tax amount is allocated even though only the residential share is allocable
• Mixed-use buildings (residential + commercial) are not separated
• The new property tax after the reform is higher than before — without a comprehensible explanation

Tip: It can make sense to ask the landlord for the property tax notice. Comparing the amount shown there with the bill can reveal possible discrepancies. In mixed-use buildings, the commercial share must be deducted where required.

Conclusion: Checking Is Worthwhile

Nebenkostenabrechnungen are complex — and that is exactly what some landlords take advantage of, knowingly or unknowingly. The good news: tenants have strong rights. A careful review of the bill is worthwhile, and if errors are found, an objection is possible.

Further reading:

• Objection: template, deadlines & guide
• All deadlines for tenants at a glance
• Utility costs too high? How to check your bill

If you are unsure whether your bill is correct: NeKo Check reviews your Nebenkostenabrechnung automatically — quickly and simply.

Frequently Asked Questions