Free · iPhone, iPad and Mac
Your digital certificate, on every device you sign from.
Many government forms, banks and employers ask for a signature made with a certificate, not a drawing. Keepsign signs with your Digital ID on iPhone and iPad as well as on the Mac, and checks the certificate signatures you receive.
●Ana Ruiz · valid
Signed with a certificate · PAdES · timestamped
The document hasn’t changed since she signed.
●You · valid, with permitted later changes
Your Digital ID · signed on iPhone
After your signature: 1 form field filled.
Issued by your certificate authority · valid until 2028
Chain checked on this device. Check online asks the issuer if it was revoked, only when you tap it.
A drawing shows intent. A certificate proves who.
Both are free in Keepsign. They do different jobs, and it helps to know which one you’re being asked for.
| Drawn, typed or photo signature | Digital ID (certificate) signature | |
|---|---|---|
| What it is | An image of your signature placed on the page | A cryptographic seal tied to your certificate, stored inside the PDF |
| What it proves | That someone put that mark there | Who signed (per the certificate) and that the signed bytes haven’t changed |
| You need | Nothing | A certificate file (.p12 or .pfx) from an issuer, or a supported card or token |
| Typical use | Everyday forms, delivery notes, permission slips | Government procedures, contracts, invoices, professional documents |
Import once. Sign anywhere.
Bring your certificate
In the Digital ID tool, tap Sign with a certificate (.p12 or .pfx), pick the file and enter its password. Keep it in this device’s keychain and you won’t need the file again. Certificates are never synced to iCloud.
Choose where to sign
Use an empty signature field or draw a box. Add a visible appearance with your name and date if you want.
Confirm with Face ID, Touch ID or your passcode
The private key is only used after you confirm.
Keepsign signs in PAdES and checks the result
The signature is appended as its own revision, so earlier signatures stay valid, and the receipt shows all of them.
A verifier that tells you why.
Open a signed PDF and Keepsign shows each signature in one of four states: valid, valid with permitted later changes, not valid, or couldn’t be verified. Tap one for the certificate chain, the issuer, the signing time and any timestamp, including long-term (LT and LTA) signatures.
Checking revocation means contacting the issuer’s servers, so it only happens when you tap Check online. Without that, nothing leaves your device.
What we can’t promise
Whether a certificate signature is accepted depends on the certificate, the issuer and who receives the document. Keepsign makes a standard PAdES signature with the certificate you give it; it doesn’t issue certificates and can’t make one more trusted than it is.
Questions
Can I sign a PDF with a digital certificate on iPhone?
Yes. Import your .p12 or .pfx into Keepsign and sign from any PDF. Our step-by-step guide covers signing with a digital certificate on iPhone or iPad, including common issues with certificates installed as profiles.
Is it really free?
Yes. Signing one document at a time with a certificate is free. Pro adds signing many files in one batch.
Does it work with smart cards and USB tokens?
Keepsign can use certificates on cards and tokens that your iPad or Mac already recognises through the system. Support depends on the card and its driver, so try it with yours before you rely on it.
Why does my signature show “couldn’t be verified” on someone else’s computer?
Usually because their software doesn’t trust your certificate’s issuer yet. The signature can be intact and still show as unknown. Here is how to tell the cases apart.
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