The provision of ICT servicesmeans digital and data services provided through ICT systems to one or more internal or external users on an ongoing basis, including hardware as a service and hardware services which includes the provision of technical support via software or firmware updates by the hardware provider, excluding traditional analogue telephone services; to financial entitiesas defined in Article 2, points (a) to (t) may rely on potentially long or complex chains of subcontracting which should be monitored by the financial entitiesas defined in Article 2, points (a) to (t). Financial entitiesas defined in Article 2, points (a) to (t) should assess the associated risks, including ICT third-party concentration risks with regard to the ICT third-party service providersmeans an undertaking providing ICT services; supporting a critical or important functionmeans a function, the disruption of which would materially impair the financial performance of a financial entity, or the soundness or continuity of its services and activities, or the discontinued, defective or failed performance of that function would materially impair the continuing compliance of a financial entity with the conditions and obligations of its authorisation, or with its other obligations under applicable financial services law; or material parts thereof, considering a risk-based approach and the principle of proportionality. To enable that assessment, financial entitiesas defined in Article 2, points (a) to (t) should be required to record in the register of information only those subcontractors that effectively underpin ICT servicesmeans digital and data services provided through ICT systems to one or more internal or external users on an ongoing basis, including hardware as a service and hardware services which includes the provision of technical support via software or firmware updates by the hardware provider, excluding traditional analogue telephone services; supporting critical or important functionsmeans a function, the disruption of which would materially impair the financial performance of a financial entity, or the soundness or continuity of its services and activities, or the discontinued, defective or failed performance of that function would materially impair the continuing compliance of a financial entity with the conditions and obligations of its authorisation, or with its other obligations under applicable financial services law; or material parts thereof, including all the subcontractors providing ICT servicesmeans digital and data services provided through ICT systems to one or more internal or external users on an ongoing basis, including hardware as a service and hardware services which includes the provision of technical support via software or firmware updates by the hardware provider, excluding traditional analogue telephone services; whose disruption would impair the security or the continuity of the service provision. When identifying those subcontractors, financial entitiesas defined in Article 2, points (a) to (t) should consider business and ICT service continuity and ICT security aspects.