The concept of at least two signatures being required for payments release has not been mentioned in regulatory provisions on PIS (PSD2, RTS, EBA opinions, ...). So far, it is neither actually covered by any of the API Standards.

This white-paper though deeply dives into the issue and explores the gaps and possible opportunities. Following topics are covered:

• Concept definitions: accountholder, mandates, payment signing rules, multisignature multichannel, mandate management.
• AS IS mandate mastering and enforcing.
• AS IS multisignature processing.
• Intersection of multisignature payments and PSD2 XS2A.
• TO BE: potential opportunities for an aggregator in facilitating co-signing of payments.

(Keep up with all the abbreviations with https://support.ibanity.com/glossary )