Service charges are separate from bare rent increases in the regulated sector. Landlords may index these annually, but exclusively on the basis of documented increases such as higher energy costs or maintenance. You are entitled to a specification by 1 July, with advance payment and final settlement. Refuse to pay in case of unclarity? File a complaint with the Rent Tribunal.
In social housing, service charges may not exceed 15% of the bare rent. For tender housing, a transparency provision applies via tender contracts. Transitional sector: cost increases are limited to proven inflation. Rent allowance covers service charges in part. In case of dispute: the court rules on reasonableness. Keep invoices and compare with neighbours. Even during corona time, relaxations applied, but now stricter control on usurious rates. This way you prevent unexpected burden increases.