EBU Single Rulebook Q&A 1 September 2021 2021_6156 Arbitrating between security and obstacles

Can an Account Servicing Payment Service Provider (ASPSP) know a mobile phone number inside of the Third Party Provider (TPP)’s organisation in order to send a decryption password to the TPP out-of-band via SMS? As a general principle of PSD2, security of operations is of utmost importance.