OPTA regulates providers of public electronic-communications services (such as telecom providers) in the Netherlands. The costs of these regulatory activities are covered in part by these providers themselves. In this letter, OPTA requests public electronic-communications providers to declare their turnovers. OPTA uses this information to determine the fees that providers are required to pay. Providers are statutorily required to declare their turnovers to OPTA every year in order for ACM to determine the regulatory costs. The fee that providers are due for is based on the net turnovers in 2011.