Dienst Toeslagen (the Dutch benefits office) receives your new address automatically through the municipality, but you have to report your new rent and service charges yourself through Mijn toeslagen. Do this as soon as you have the tenancy agreement.
If anything else changes in your household, for example because you are moving in with a partner, report that too. That way you avoid having to pay money back later. You can check in advance whether you are entitled to housing benefit (huurtoeslag) in your new home with the trial calculation on the Dienst Toeslagen website.
