How OTP e-signature works, and what it proves
The tenant's identity check, and the legal basis behind the signed PDF Keyio generates.
How signing works
When a tenant is asked to sign, they first compose their signature in the app — drawing, typing, or uploading it. Keyio then emails a one-time code (OTP); entering that code verifies their identity and finalizes the signature. Once everyone required has signed, Keyio generates the final signed PDF with a certificate page attached: who signed, when, from which IP address, and by what method.
What this proves legally
This is an OTP-verified simple electronic signature with a full audit trail — recognized under Spanish contract law (Art. 1278 Código Civil, which establishes that contracts are binding regardless of the form used to express consent) and the EU eIDAS framework's category for simple electronic signatures. It is not an advanced or qualified electronic signature under eIDAS — there's no certificate authority or cryptographic signing key involved, so it should not be described that way.
The certificate page is attached to the final PDF automatically — you don't need to request or generate it separately.