How to sign a PDF on an iPhone

If you only need to sign your own PDF on iPhone, use Apple’s built in Preview or Markup tools. Apple says Preview on iPhone can fill out and sign PDF forms, and supported apps can add signatures with Markup. Preview on iPhone Fill out forms, sign documents, and create signatures on iPhone If you need to send a PDF to someone else for signature, use a signing workflow made for requests and tracking, such as SignKaro or Adobe Acrobat Sign.

The right method depends on whether the file is a fillable form, a plain PDF, or a document you need to send out for other people to sign. Apple says Preview on iPhone can open and view PDFs, including PDF attachments, and it can handle forms with fill fields and signature fields. Open and view PDFs and images in Preview on iPhone Preview on iPhone

If you want to send and collect signatures from other people on a phone or browser, see sign a PDF online.

Check the PDF type before you start

Start by checking what kind of PDF you have. Some PDFs are prepared forms with fillable fields and a signature field, while others are flat files that need markup. Apple’s Preview flow begins with a Form Filling button when the PDF is set up that way. Preview on iPhone

If the PDF came in Mail, open it in Preview. Apple says you can add PDF attachments in Mail, then open the attachment on iPhone and work with it there. Add email attachments in Mail on iPhone If you scanned the document from paper, Apple says you can scan documents on iPhone or iPad and save them as a PDF. How to scan documents on your iPhone or iPad

A quick check helps. If the PDF is a form, use the form fields. If it is a flat PDF, use the signature tools. If the file came from a scan in Mail or Notes, the iPhone can still handle it as a PDF.

Sign a PDF with Apple’s built in tools

Open the PDF attachment in Mail, then open it in Preview. Apple says Preview can open PDFs attached in Mail, so you can stay on the iPhone while you work. Open and view PDFs and images in Preview on iPhone

Tap the Form Filling button, then tap each field and enter the required text. If the PDF has a signature field, sign with your finger inside that field. Apple says this is the normal Preview flow for PDF forms, including signing documents and creating signatures. Preview on iPhone Fill out forms, sign documents, and create signatures on iPhone

If the PDF does not already include a signature field, use Markup instead. Tap Add, then Add Signature in a supported app, and place the saved signature where it belongs. Apple says this is how you add a signature on iPhone outside a prepared signature field. Fill out forms, sign documents, and create signatures on iPhone

For example, a 2 page vendor agreement sent by email can be signed and returned from the same phone in a few taps if the file already has fields. That is an example only, not a promise for every file.

After you sign, save or send the updated PDF from the same screen. If you received the file by email, Apple’s reply flow lets you send back the signed PDF as an attachment. Reply to an email with a PDF attachment in Preview on iPhone

Use Adobe Acrobat on iPhone when the file needs fill and sign tools

If you prefer a dedicated PDF app, Adobe Acrobat on iPhone is another option. Adobe says the mobile app supports Fill & Sign, and the menu includes Signature and Add signature.

Adobe’s mobile help says you can create a signature by drawing it, using an image, or capturing one with the camera. You can then move and resize it before tapping Done to save.

One limitation matters: Adobe says some form types, including XFA forms, are not supported on mobile. If a file fails on the phone, you may need desktop handling or a different workflow.

If your goal is a simple upload, field placement, and emailed signed PDF with an audit certificate, SignKaro is one option. It is not Aadhaar eSign or a DSC. It also does not replace a workflow that a sender needs to track multiple signers in another system.

Send a PDF for someone else to sign

There is a difference between signing your own PDF on iPhone and sending a PDF to other people for signatures. Apple’s built in tools are mainly for local signing on your device, while Adobe Acrobat Sign is the mobile workflow for collecting signatures from others.

On Adobe’s mobile flow, open the document in the waiting list, tap the document, then tap the Sign icon and follow the required fields. This is a workflow overview, not a promise that every business process looks the same.

If you want to tidy the PDF before sending it out, see edit a PDF before signing.

Copyable checklist for signing on iPhone

Use this checklist before you sign or send the file.

Check whether the PDF is a form with fields or a flat file.
Open the file in Preview if it came by Mail.
Use Form Filling for fillable fields.
Use Markup and Add Signature if there is no signature field.
Save or reply with the updated PDF.
If you need to collect signatures from other people, use a signing workflow built for requests and tracking.
If the file fails on mobile, check whether it is an unsupported type such as XFA on Adobe mobile.

Common mistakes and the fix for each

Mistake 1: assuming every PDF signs the same way. Fix: check whether it is a form with fields, a flat PDF, or an unsupported type such as XFA on mobile.
Mistake 2: looking for a signature field that is not there. Fix: use Markup plus Add Signature if the document is a plain PDF, not a prepared form.
Mistake 3: forgetting to save or send the updated file. Fix: finish with Done in Adobe, or send the file back from Mail after Preview.
Mistake 4: using a local signature when the sender wants tracking, reminders, or multiple signers. Fix: use a full e signature flow instead of one off markup.

FAQ

Can I sign a PDF on iPhone without an app?

Yes. Apple says Preview and Markup on iPhone can fill out and sign PDF forms, and supported apps can add signatures with Markup. Preview on iPhone Fill out forms, sign documents, and create signatures on iPhone

Can I sign a PDF someone emailed me?

Yes. Apple says you can open a PDF attachment from Mail in Preview and complete it there. Open and view PDFs and images in Preview on iPhone

Can I send a PDF for signature from my iPhone?

Yes, but use a signing workflow made for requests and tracking. Adobe Acrobat Sign is the mobile workflow for sending documents to other signers.

Can I scan a paper document and then sign it?

Yes. Apple says you can scan documents on iPhone or iPad and save them as a PDF, then open that PDF on the phone and sign it. How to scan documents on your iPhone or iPad

How to sign a PDF on an iPhone