How to sign a PDF on iPhone with Markup — and when a signing app helps
For one document, start with Apple’s built-in tools. Open the PDF in Preview or Files, use Markup or form filling to add a signature, position it, and save a copy. Apple’s iPhone guide covers that workflow.
ScanLens is useful when you sign often, need reusable signatures or initials, or want to scan paper and return a signed PDF without moving between apps. Signatures are stored on the iPhone and can be placed, resized, and rotated on the page.
ScanLens is a free app: open a PDF from Mail or Files, add your signature, export the signed copy, and send it back.
A signature placed on a PDF is a simple electronic signature. It is accepted for many routine agreements, but the requirement depends on the document and jurisdiction. Some transactions need identity verification, an audit trail, notarization, or a qualified electronic signature. See the e-signature legality guide before relying on a visual signature for a regulated or high-value document.
After signing, you can password-protect the PDF or make it smaller for email before sharing it.
Are iPhone PDF signatures legally binding?
Often, but not automatically. Electronic-signature laws generally allow many contracts to be signed electronically, while the required level of identity verification and evidence depends on the document, the parties, and the jurisdiction.
E-Signature Laws in the United States: ESIGN Act
The Electronic Signatures in Global and National Commerce Act (2000) gives e-signatures the same legal status as handwritten signatures for interstate and foreign commerce. State-level UETA (Uniform Electronic Transactions Act) laws provide additional backing in 47 states.
E-Signature Laws in the European Union: eIDAS
The eIDAS Regulation (2014) establishes a legal framework for electronic signatures across all EU member states. Simple electronic signatures (like those created on iPhone) are legally valid for most transactions, with higher-security "qualified" signatures for sensitive documents.
International E-Signature Recognition
Canada, Australia, the UK, Japan, China, India, and Brazil have all enacted e-signature laws. Most follow similar principles: electronic signatures are valid if the signer intended to sign and the signature can be associated with the document.
Documents That Still Need Ink Signatures
Some documents still require traditional signatures in many jurisdictions:
- Wills and testamentary trusts
- Certain family law documents (adoption, divorce in some states)
- Court orders and notices
- Utility cancellation notices (varies by state)
- Some real estate documents (varies by state)
For most everyday documents—contracts, agreements, consent forms, authorizations—e-signatures are fully accepted and legally enforceable.
Tips for Better iPhone PDF Signatures
Create a Clean Digital Signature on iPhone
Use finger input to draw signatures and annotations on iPhone, and zoom in for precision.
Save Your Signature for Reuse
Create your signature once and save it. This ensures consistency across all your signed documents and saves time. You can create multiple saved signatures—perhaps a formal version and casual initials.
Position the Signature Precisely
Zoom in on signature lines for precise placement. A signature that's clearly on the intended line looks more professional than one that's oddly positioned or overlapping other text.
Review the Signed PDF Before Sending
Scroll through the entire document after signing. Make sure all required signatures, dates, and initials are in place. Missing a signature on page 5 of 10 means starting the process over.
