Can my energy supplier raise my monthly advance?
Yes — but only if your actual consumption (or tariffs) rose significantly, and only with proper substantiation. Unreasonable hikes you can refuse.
Your monthly advance is an estimate based on expected annual consumption × tariff. The supplier may adjust when (a) measured consumption has demonstrably risen, (b) tariffs changed significantly, or (c) the annual statement showed a large balance. NOT allowed: arbitrary increases to manage the supplier's cashflow. Requirements: written notice, transparent calculation, reasonable lead time (minimum 30 days). Think it's unreasonable? Request the calculation in writing, keep paying the old advance, and on refusal send a formal notice. On conflict: Geschillencommissie Energie.