Build the register as linked tables. The official ITS uses predefined columns with an indefinite number of rows, and the same contract, entity, provider, function, and ICT service identifiers must reconcile across templates.
Use the contractual arrangement reference number as the contract key. Use the financial entity LEI, ICT third-party provider identifier, function identifier, and ICT service type code to connect each contract to the entity using the service, the provider chain, the supported function, and the assessment record. Each data element holds one value; where several values are valid, add a row for each value as the ITS requires.
Scope the register before mapping fields. Include every direct provider arrangement for an ICT service, whether or not procurement calls it outsourcing. Add subcontractors where they effectively underpin an ICT service supporting a critical or important function or a material part of one. Keep non-ICT goods and services outside this register unless the arrangement also contains an ongoing ICT service. Where an ICT intra-group provider uses subcontractors, include at least the first extra-group subcontractor even when the ICT service does not support a critical or important function or material part.