E-signature API Integration: DocuSign, Adobe Sign, and Yoti
E-signature APIs embed document signing workflows directly into your application — enabling contracts, agreements, and consent forms to be signed electronically with full legal validity. E-signatures are legally equivalent to wet signatures in the UK, EU (under eIDAS), USA, and most jurisdictions worldwide.
E-signature Validity
Electronic signatures are legally valid for most commercial and consumer agreements. Key legislation: UK Electronic Communications Act 2000, EU eIDAS Regulation, US ESIGN Act. Exceptions: wills, real estate transfers, and court orders — some jurisdictions require wet or qualified signatures for specific document types.
Signature Types
- Simple Electronic Signature (SES): Click-to-sign, name typed, checkbox agreement. Legally valid but minimal identity verification.
- Advanced Electronic Signature (AES): Identity verified, unique to signatory, detects document changes after signing. DocuSign, Adobe Sign operate at this level.
- Qualified Electronic Signature (QES): Based on qualified certificate with identity verification meeting eIDAS standards. Highest legal standing — required for some regulated use cases.
Major Platforms
- DocuSign: Market leader — extensive API, comprehensive envelope/workflow management, strong integrations
- Adobe Sign: Good for Adobe Acrobat ecosystems, Microsoft integration
- Yoti: UK-based, strong identity verification alongside signing, GDPR-focused
- Dropbox Sign (formerly HelloSign): Developer-friendly API, competitive pricing
- Signable: UK-focused, simple pricing, good for SME use cases