Guide

How to Sign a PDF on iPhone

Short answer: To sign a PDF on iPhone or iPad, open the document in PDF JustFit, place a handwritten signature with Apple Pencil or your finger, position it on the page, and export a flattened PDF.

When you need this

  • A contract or form has arrived and needs your signature.
  • You have no printer, or printing and scanning would be slower.
  • You need to sign and return the document the same day.
  • The form also needs a name, date or role typed next to the signature.

Steps

  1. Open the PDF in PDF JustFit

    Load the document from Files, or send it from Mail using the share sheet.

  2. Choose the signing tool

    Draw your signature with Apple Pencil on a supported iPad, or with your finger on iPhone or iPad.

  3. Place and size the signature

    Position it on the signature line and resize it to fit the space.

  4. Add text if the form needs it

    Use the text tool to add a name, date or role alongside the signature.

  5. Export flattened

    Export a flattened, share-ready PDF in a single tap, then send it back.

Signing and marking up a PDF in PDF JustFit with highlight and ink tools
Markup and signing tools in PDF JustFit: highlight, draw, erase and add text, then export a flattened PDF.

Sign where the document arrived

PDF JustFit includes signing alongside compression, conversion and annotation, so a document can be received, reviewed, signed and returned from one app on iPhone or iPad.

Flattened, share-ready output

A flattened PDF merges the signature into the page, so the result is predictable in other apps and the signature cannot be separated from the document.

Privacy and limitations

This is a visual signature, not a certificate

PDF JustFit places a handwritten signature on the page. It is not a certificate-based digital signature service, so check whether the recipient requires a certified signing workflow.

Compress before sending if needed

If the signed document still exceeds an email limit, compress it to a target size before attaching it.

Frequently asked questions

How do I sign a PDF on my iPhone?

Open the PDF in PDF JustFit, place a handwritten signature with Apple Pencil or your finger, position it, and export a flattened PDF.

Does PDF JustFit support Apple Pencil?

Yes. The product description states that Apple Pencil is supported for signing and annotation.

Can I add a date or name next to my signature?

Yes. PDF JustFit lets you add text as well as a signature, so a form that requires a name, date or role can be completed in the same pass.

Keep your documents light, organized and private

PDF JustFit: Compress, AI Chat is available on the App Store for $9.99. Requires iOS/iPadOS 26.5 or later.