Yes, to use of our payment services your company has to be registered with the Chamber of Commerce of your country. For nearly all payment methods, we can only legally pay out to companies registered with the trade register of the country where the company is domiciled. For Dutch companies, this is the Chamber of Commerce, but in Belgium, for instance, this means a registration with the Crossroads Bank for Enterprises (CBE).
See for more information about setting up your Mollie account: How do I sign up for Mollie?