EBU Single Rulebook Q&A 13 September 2018 2018_4272 Payment accounts and reference accounts

Are payment accounts, which are coupled with a reference account, in scope of PSD2 especially Regulation (EU) 2018/389 – RTS on strong customer authentication (SCA) and secure communication (CSC)? The payment accounts of our customers are coupled with a reference account. The account owner has to be the same person for payment account and reference account.