How to Sign a PDF on iPhone for Free

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Last reviewed: October 15, 2026 by the Smart Savings Guides editorial team. How we research and update articles.

Need to sign a form, lease or permission slip? You can sign a PDF on your iPhone for free with the built-in Markup tools in Files and Mail, and on iOS 26 and later with Apple's Preview app. No printing, scanning or paid app needed. Here's how.

Step 1: Open the PDF

Open it in Files or Mail. If it arrived as an email attachment, tap it in Mail, or save it to Files first so you keep a copy. If you have a paper document, scan it first: see how to scan to PDF on iPhone.

Step 2: Markup

Tap the Markup icon, then the plus, then Add Signature. 1. In Files, open the PDF and tap the Markup button (a pen tip). 2. Tap the plus (+) button in the toolbar. 3. Choose Add Signature. 4. If it's your first time, sign with your finger (or Apple Pencil on iPad) and tap Done. iOS saves the signature for next time.

Step 3: Save and send

Place it, tap Done, and share. 1. Drag the signature to the signature line and pinch or drag the corners to resize it. 2. Tap Done to save the changes to the PDF. 3. Tap Share to send it by Mail, Messages or another app.

Signing in Mail

When you reply to an email with a PDF attachment, you can tap the attachment, tap Markup, add your signature and tap Done. Mail inserts the signed version into your reply. This is handy when someone emails a form and wants it back signed.

Filling in form fields

Many PDFs have fillable fields for names and dates. - Files or Mail: use the Markup Text tool (under the plus button) to type text where needed. - Preview (iOS 26 and later): open the PDF in Preview and use the form tool to fill highlighted fields, with AutoFill suggestions where available.

Methods compared

Is a Markup signature legally valid?

In many countries, including the US under the federal E-SIGN Act, electronic signatures are generally legally valid for most documents. Some documents, such as certain wills or notarized forms, may need a wet signature or special process. If you're unsure, ask the person requesting the signature which format they accept. This isn't legal advice.

E-signature requests from DocuSign and others

If someone sends you a signing link from an e-signature service, open the email on your iPhone, tap the link and follow the prompts. You don't usually need an account to sign as a recipient. Be wary of unexpected signing requests: phishing emails often imitate e-signature services. Check the sender's address and don't enter passwords on unfamiliar pages.

Managing saved signatures

iOS stores signatures you create. To add or delete one, open Markup, tap the plus button, then Add Signature, and use the options to add or remove signatures. Delete a saved signature if you share your device.

Tips for a clean signature

• Turn your iPhone sideways for more room when drawing.
• Sign slowly; you can clear and redo it.
• Resize the signature to fit the line, not cover nearby text.
• Check the final PDF before sending.

Protecting signed documents

Signed contracts and forms can contain personal details. Store them in a folder you control, avoid sending them over unsecured channels when a secure portal is offered, and delete copies you no longer need. If the recipient requires a fax, see how to send a fax from your iPhone.

Adding the date and your initials

Many forms ask for a date or initials on each page. Use the Text tool under the plus button to type the date, and add a second saved signature with just your initials for pages that need them. Zoom in with two fingers before placing small text, so it lines up neatly with the field.

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