How to Sign a PDF on iPhone (2026)

Your iPhone can already sign a PDF for free — no app to install — if all you need is to drop your own signature onto a document and send it back. The tool is called Markup, it’s built into the Files app and Mail, and it takes about thirty seconds once you know where to tap. But Markup has hard limits: it can’t request a signature from someone else, it doesn’t record who signed or when, and it produces no tamper-evident record. This guide shows you the built-in method step by step, tells you honestly where it stops being enough, and then walks through signing or sending a PDF with sign.pink for the times you need a legally-binding signature with a real audit trail.

Method 1: Sign a PDF for yourself with iOS Markup (free)

This is the right method when you are the one signing a document someone sent you — a release form, a one-page agreement, a school permission slip — and you just need to add your signature and send it back. It’s entirely free and works offline.

Signing a PDF in the Files app

• Open the Files app and tap the PDF to open it.
• Tap the Markup icon (the pen tip inside a circle) in the top-right corner.
• Tap the plus (+) button, then choose Signature.
• If you’ve saved a signature before, tap it. Otherwise tap Add or Remove Signature, then Add Signature, and draw your signature with your finger or Apple Pencil. Tap Done.
• Your signature drops onto the page. Drag it into position and pinch to resize it.
• Tap Done to save. The signed PDF replaces the original in Files.

Signing a PDF attached to an email

• In the Mail app, open the email and tap the PDF attachment to preview it.
• Tap the Markup icon in the top-right corner.
• Tap the plus (+) button, choose Signature, and place your saved or newly drawn signature.
• Position and resize it, then tap Done.
• Mail offers to reply with the signed copy attached — tap Done and send it back.

What iOS Markup can and cannot do

Be clear-eyed about what you’re getting. Markup is genuinely useful, but it’s a drawing tool, not a signing platform.

What it does well:

• Adds your hand-drawn signature image to a PDF, free and offline.
• Lets you add text and dates by hand using the text tool.
• Saves a signature so you can reuse it next time.

What it cannot do:

• It can’t send a document to someone else to sign. Markup only adds your mark to a file already on your phone. There’s no way to request a signature from a counterparty.
• It keeps no audit trail. There’s no record of who signed, when, from what device, or whether the file was altered afterward. A drawn image is trivially easy to copy from one PDF and paste onto another.
• It has no identity step. Anyone holding the phone can drop the saved signature onto any document.
• It can’t fill multi-party forms in order. If a document needs you to sign, then your business partner, then a witness, Markup has no concept of turns.

For a quick form you’re returning to a friend, none of that matters. For a contract that might be questioned later, it matters a lot.

Method 2: Send or sign a PDF with sign.pink (legally-binding, with audit trail)

When the document is consequential — a freelance contract, a lease, an NDA, anything where you’d want proof later that the right person signed — you need more than a drawn picture. You need a record. sign.pink is a $3/month, mobile-first DocuSign alternative with no envelope caps and no per-seat fees, and crucially, the people you send to never need an account. The whole flow works in your iPhone’s browser, so there’s nothing to install. You can read more about how the on-phone experience is built on the mobile signing page.

How to send a PDF for someone else to sign

This is the gap Markup can’t fill. Here’s the full flow from your iPhone:

• Open sign.pink in Safari (or any browser) on your iPhone.
• Upload your PDF — from Files, iCloud Drive, or straight from a photo of a paper document.
• Add the recipient’s name and email. They won’t be asked to register; see no-account signing for how that works.
• Drag signature, date, initial, and text fields onto the document where each person needs to act.
• If more than one person signs, set the order so it routes to each signer in turn using signing order.
• Tap Send. Your recipient gets an email link, opens the PDF in their own browser, signs with a finger or trackpad, and submits.
• Everyone receives the completed, signed PDF, and a record is generated automatically.

For more on routing documents to multiple parties, the send for signature page covers the full workflow.

How to sign a PDF yourself with a real record

You can also use sign.pink for documents you’re signing on your own end — the difference from Markup is that you get a verifiable record instead of a pasted image:

• Open sign.pink in your browser and upload the PDF.
• Tap where you need to sign and draw or type your signature.
• Add any dates or text the document requires.
• Finalize. You get the signed PDF plus a certificate of completion.

If you just want to test the experience on a single document without committing, you can sign a PDF online free first and see the finished file before deciding.

Why the audit trail is the real difference

The thing iOS Markup fundamentally lacks is evidence. When you sign or send through sign.pink, the platform captures a tamper-evident audit trail: who signed, the email they signed from, timestamps for each action, and a hash that detects whether the document was changed after signing. If a signature is ever disputed, that record is what turns “I think they agreed” into something you can actually show. A drawn image from Markup carries none of this context with it.

Which method should you use?

The decision is simple once you frame it around two questions: who’s signing, and how much does proof matter.

• Use iOS Markup when you are signing your own document, it’s low-stakes, and you just need to send it back quickly. Free, fast, no setup.
• Use sign.pink when you need to send a PDF for someone else to sign, when more than one person signs, or when the agreement is important enough that you’d want a defensible record later.

Plenty of people start with Markup and outgrow it the first time they need a counterparty’s signature on something that matters. At $3/month with no envelope limits, sign.pink covers that without the per-document anxiety of legacy tools — you can compare the full breakdown on the pricing page.

Are signatures from these methods legally binding?

In the United States, electronic signatures are recognized under the federal ESIGN Act (2000) and the Uniform Electronic Transactions Act (UETA), a 1999 model law adopted by 49 states plus the District of Columbia (New York is the holdout, relying instead on its own Electronic Signatures and Records Act). Across the European Union, electronic signatures are governed by the eIDAS Regulation (EU) No 910/2014, which recognizes simple, advanced, and qualified electronic signatures (SES, AES, and QES). Under these frameworks, a signature isn’t invalid simply because it’s electronic. What strengthens enforceability is the ability to prove intent, attribution, and that the document wasn’t altered — exactly the evidence US Federal Rules of Evidence 901 and 902 concern themselves with when a record is introduced.

A signature drawn in Markup can satisfy the basic definition of an electronic signature, but it travels with no supporting evidence. The captured audit trail from a platform like sign.pink is what helps demonstrate who signed and that nothing changed afterward — the difference between a signature and a signature you can stand behind.

This article is general information, not legal advice; consult a qualified attorney about your specific situation.