Fewer than 500 tenants have so far requested a review of their rental costs at Berlin state housing companies such as Degewo. The figure is well below expectations, despite the rent price brake having been in place for years and many households in the capital struggling with high housing costs. For housing companies, this currently means hardly any administrative effort. The low utilization suggests information deficits or uncertainty among tenants – and raises the question of whether the instrument actually has an effect in practice.