# psd2

Source: https://startwithidentity.com/glossary/psd2/
Last updated: 2026-08-29
License: content by Start with Identity. Cite the source URL.

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Revised Payment Services Directive. EU regulation requiring Strong Customer Authentication for electronic payments and enabling open banking. SCA mandates two-factor authentication with specific dynamic linking requirements.

PSD2 is the reason European checkout flows look the way they do, and dynamic linking is the requirement most often implemented poorly: the authentication has to be bound to the specific amount and payee, shown to the user, so an approval cannot be replayed against a different transaction. That constraint is why generic push approvals do not satisfy it.

See also: [SCA](https://startwithidentity.com/glossary/sca/), [FAPI](https://startwithidentity.com/standards/fapi/), [step-up auth](https://startwithidentity.com/glossary/step-up-auth/), [identity regulations](https://startwithidentity.com/regulations/)