The present document@ based on the general policy requirements specified in ETSI EN 319 401 [2]@ specifies policy and security requirements for signature validation services operated by a TSP. NOTE 1: Beside signature validation@ other signature services@ like signature creation@ signature augmentation or signature preservation can also be offered by TSPs. Such services can be provided as stand-alone services or combined (e.g. augmentation can be used to support a preservation service). The present document does not provide requirements on signature services beyond validation and does not provide requirements on how to combine signature related services. NOTE 2: A distinct Technical Specification (TS) provides policy and security requirements for TSP offering signature augmentation services as a stand-alone service or in complement to one of the above-mentioned services. The present document is aimed at trust services supporting the validation of digital signatures in accordance with ETSI TS 119 102-1 [3]. It takes into account the relevant requirements for signature validation application specified in ETSI TS 119 101 [1] as they relate to TSPs. It is aimed at supporting the validation of digital signatures in European and other regulatory frameworks. NOTE 3: Specifically@ but not exclusively@ the present document is aimed at qualified and non-qualified trust services@ supporting the validation of digital signatures in accordance with the requirements of the Regulation (EU) No 910/2014 [i.1] for validation of electronic signatures and electronic seals (both advanced and qualified). Annex B complements the requirements for signature validation service providers offering a Qualified Validation Service for qualified electronic signatures or for qualified electronic seals as specified by Regulation (EU) No 910/2014 [i.1]. NOTE 4: Specifically@ but not exclusively@ digital signatures in the present document cover electronic signatures@ advanced electronic signatures@ qualified electronic signatures@ electronic seals@ advanced electronic seals@ and qualified electronic seals as per Regulation (EU) No 910/2014 [i.1]. The present document may be used by competent bodies as the basis for confirming that an organization is trustworthy in validating digital signatures on behalf of other persons or on its own behalf. NOTE 5: See ETSI EN 319 403 [i.13] for guidance on assessment of TSP processes and services. The user's interface is outside the scope of the main TSP service. However@ the present document provides in annex D recommendations for the user's interfaces (for inputting the request and to visualize the validation report). The TSP has connections with external (trust) services that can be contacted for provisioning validation information@ or to relay the validation request. The present document does not put requirements on the trust service policies applied by such external services. The present document identifies specific controls needed to address specific risks associated with validation services.