Abstract: There are provided methods and corresponding systems for supporting Internet of Things (IoT) Trustworthiness as a Service (TaaS) related to an IoT device. The IoT device being arranged for connection to the Internet via a wired or wireless communication system. A method is based on an automated request-response procedure performed by a network entity acting as TaaS consumer, TaaS receiver or TaaS proxy to obtain a digital IoT certification proof representative of the trustworthiness of the IoT device from an IoT certification system acting as TaaS provider. The automated request-response procedure comprises requesting the digital IoT certification proof from the TaaS provider based on an identifier for locating the digital IoT certification proof for the IoT device, and receiving a response comprising the digital IoT certification proof from the TaaS provider to enable management and/or assessment of the trustworthiness of the IoT device.