Overview
- Landlords must deliver an annual operating-cost statement within 12 months after the end of the billing period and cannot normally claim back payments if they miss that deadline.
- Tenants have 12 months after receipt to check the statement and formally contest any item or position shown on the bill.
- Common formal defects that can invalidate a whole statement include missing totals, no clear distribution key, or omission of recorded advance payments.
- The 2023 CO2 cost-allocation law requires landlords to show the CO2 split and subtract their share; if the calculation is missing tenants may reduce their heating charge by three percent.
- Tenants can demand to see and copy original invoices for large or unexplained increases, should consider paying under protest to avoid contract risk, and face interest or legal enforcement if they simply ignore valid demands.