Nebenkosten Suddenly Higher? What Your Landlord Has to Get Right First

A noticeably higher Nebenkosten advance payment often feels arbitrary to tenants. In reality, an adjustment up or down is clearly regulated by law and tied to specific conditions your landlord actually has to meet.

When an adjustment is allowed at all

Under § 560 BGB, an advance payment for operating costs can only be adjusted after a statement has been issued. Either party can then declare, in text form, an adjustment to a reasonable amount. Raising the prepayment out of the blue, without a prior statement showing an actual shortfall, isn't allowed.

What applies to a flat-rate Nebenkosten arrangement

If a fixed flat rate was agreed instead of an advance payment, different rules apply. The landlord may only pass on increases in operating costs if the rental contract explicitly allows it, and must name and explain the reason for the increase in the declaration. Under § 560 BGB, the increase takes effect from the month after next following the declaration, but can apply retroactively back to the start of the year if the landlord acts within three months of learning about the cost increase.

What happens if costs go down

The same rule works in the other direction: if actual operating costs fall, an agreed flat rate has to be reduced accordingly, and the landlord must inform the tenant of this without delay. In practice, this obligation gets followed less often than an increase would, but it's just as binding.

Why a rise isn't automatically invalid

Rising energy prices or a higher regional Betriebskostenspiegel aren't, on their own, grounds for complaint. The Deutscher Mieterbund regularly points out that nationwide averages can climb year over year without that indicating an error. What matters is whether the formal requirements for the adjustment were met, not the size of the increase itself.

What to check when you receive an increase notice

Ask for the underlying Nebenkostenabrechnung if you haven't already received it, and check whether the declaration is in writing or text form and names the reason for the increase. If either requirement is missing, the adjustment can be formally challenged.

If you want to know whether your prepayment even looks reasonable to begin with, our guide on how high Nebenkosten can legally run relative to rent explains what counts as excessive. And if your rental contract doesn't set out a prepayment or flat rate at all, see what that means in our guide to Nebenkosten in the rental contract. For a full breakdown of what drives costs up in the first place, check our monthly utility cost breakdown.