Why the customer asks this
An essential or important entity must arrange the security of its supply chain, including the relationship with direct suppliers and service providers [1]. Its policy concerns suppliers and service providers whose products and services can affect the security of its network and information systems [4]. It takes into account the vulnerabilities and the security practices of each direct supplier [2] and periodically checks whether that supplier meets its security requirements [3].
What that means for you
If you are not covered yourself, you have no reporting duty or registration duty and your management body does not need a certificate. Your customer can, however, impose contractual requirements, send questionnaires or ask for evidence of, for example, backups, access management and incident agreements. That matters especially if you are connected to its systems (EDI, portal, shared planning) or process its data. Ask which requirements the customer derives from its risk analysis; that makes the discussion concrete.
First check whether you really are not covered
Whether you are covered by the Cbw yourself depends on your activity and your size. A company from Annex 1 that is larger than medium-sized is an essential entity [5]. A medium-sized company from Annex 1 and a medium-sized or larger company from Annex 2 is an important entity [6]. That size limit also applies to postal and courier services that carry out at least one step of the postal delivery chain (Annex 2) [7] and to providers of managed IT or security services to other companies (Annex 1) [8].
If you are smaller than medium-sized, you are as a rule not covered. Exceptions are: you have been designated as a critical entity under the Wet weerbaarheid kritieke entiteiten [9], the minister designates you as an essential entity [10], or before 16 January 2023 you were designated as a provider of an essential service under the Wet beveiliging netwerk- en informatiesystemen and the minister designates you as an essential entity [11]. In addition, some digital providers are covered regardless of their size, such as qualified trust service providers and DNS service providers [12]. Providers of managed IT services are not among them.