Signatures Acrobat recognizes
Acrobat's signature panel shows your name, the signing time and that the document has not been modified.
Cert Sign
Sign PDFs with your digital certificate
Your certificate, your iPhone, done in a minute. Import your .p12 or .pfx once, place a visible signature anywhere on the page, and share a signed PDF anyone can verify.
iPhone · iPad · Mac
Works with any .p12 or .pfx certificate — if it signs on your computer, it signs here.
Signing and validation, like in Adobe Acrobat
The two Acrobat features you need for signed PDFs, on your iPhone, iPad and Mac.
Built-in PDF validator
Open any signed PDF and get the same verdict Adobe Acrobat shows: valid, unknown signer or modified. Pro also runs the official EU DSS check.
Adobe and Acrobat are trademarks of Adobe Inc. Cert Sign is not affiliated with Adobe.
Signed in three steps
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1
Import your certificate
Open your .p12 or .pfx file once. The password is kept safe behind Face ID.
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2
Place the signature
Pick a PDF or scan paper, then drag the signature box exactly where it belongs.
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3
Share the signed copy
Send the signed PDF by mail, Files or AirDrop. The original stays untouched.
Everything you need to sign on the go
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Real certificate signatures
Standard PDF digital signatures that Adobe Acrobat and other readers can verify.
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Scan paper to PDF
Photograph a paper document and sign it a minute later.
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Handwriting and stamps
Draw your signature or add a company stamp next to the certificate signature.
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Protected by Face ID
Certificates and passwords stay in the device keychain, unlocked only by you.
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Trusted timestamps
Optionally add an RFC 3161 timestamp that proves when the document was signed.
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Private by design
Documents are signed on your device. No account, no cloud upload.
Questions
Which certificate do I need?
A personal or company certificate as a .p12 or .pfx file, issued by a certificate authority, for example the one you use for tax or government portals.
Will others accept my signature?
Cert Sign creates standard PDF signatures — the same kind Adobe Acrobat makes — that anyone can verify in any PDF reader. Check any signature yourself with the built-in validator, and add a trusted timestamp as proof of exactly when you signed.
Are my documents uploaded?
No. Signing happens on your device. Optional online features, like trusted timestamps, stay off until you turn them on.
How much does it cost?
You can sign one document per week for free. Cert Sign Pro unlocks unlimited signing as a weekly, monthly or one-time purchase.
Your next PDF, signed in a minute
Download Cert Sign and sign your first document today.