Your iPhone already has everything you need to sign documents: no downloads, no subscriptions, no extra steps. The built-in Markup tool lets you add a legally valid signature to PDFs, email attachments, photos of documents, and scanned paper files in under 60 seconds.
This guide covers every signing method, from native iOS tools to third-party apps, how to troubleshoot common issues, and when a regular signature isn’t enough and you’ll need a notarized signature instead.
The Fastest Way to Sign Any Document on iPhone: Using Markup
Apple’s Markup tool is built into iOS 13 and later. It requires no login and works across Files, Mail, Photos, and most document viewer apps. Here’s the universal process:
- Open your document (in Files, Mail, or Photos)
- Tap the Markup icon, the pen-tip symbol, usually in the top-right corner
- Tap the + button at the bottom of the toolbar
- Select Signature
- Draw your signature with your finger (or tap a saved one)
- Drag and resize to place it on the signature line
- Tap Done, your file saves automatically
Your signature stores automatically for future use. Every time you sign a new document, your saved signature appears as a one-tap option.
How to Sign Different Document Types on iPhone
The steps vary slightly depending on where your document lives.
Sign a PDF
Open the Files app, locate your PDF, and tap to open it fully. Tap the Markup icon (top-right), then tap + → Signature. Add, position, and resize your signature, then tap Done twice, once to confirm the signature, once to save the PDF.
Sign an Email Attachment
Open the email in the Mail app and tap the attachment. Tap the Markup icon, select + → Signature, position it, then tap Done. Tap Reply to send the signed document back directly — it attaches automatically.
Sign a Photo of a Document
If someone texted you a photo of a form or contract to sign, open it in the Photos app. Tap Edit (top-right), then tap the Markup icon (pen tip in a circle). Select + → Signature, add it, tap Done. The signed photo saves to your camera roll.
Scan a Paper Document, Then Sign It
Your iPhone doubles as a scanner:
- Open the Files app
- Tap the three-dot menu (…) → Scan Documents
- Point the camera at your document — it captures automatically
- Tap Save to create a PDF
- Open the scanned PDF, tap Markup → + → Signature
- Position your signature and save
This is the cleanest way to digitize and sign paper contracts, leases, or consent forms without leaving your iPhone.
iPhone Signing App Comparison: Which One Should You Use?
The built-in Markup tool handles most everyday signing needs. But depending on your use case, form filling, multi-signer workflows, or legal audit trails, a dedicated app may serve you better.
App | Cost | Best For | Audit Trail | Form Filling |
|---|---|---|---|---|
Markup (built-in) | Free | Quick signatures, no-frills signing | No | No |
Adobe Acrobat Reader | Free | PDFs with fillable form fields | No | Yes |
DocuSign | Free to sign | Formal contracts, sending docs to others | Yes | Yes |
SignNow | Free tier | Team workflows, multiple signers | Yes | Yes |
BlueNotary | Per session | Documents requiring notarization | Yes + notary seal | Yes |
If you just need to sign something quickly, use Markup. If you need to fill out a form with text fields and checkboxes, Adobe Acrobat Reader handles that without a subscription. For documents that require tracking, like a lease sent to a landlord or a contract sent to a client — DocuSign’s free signing tier is worth the 2-minute setup.
For documents that legally require notarization (powers of attorney, real estate deeds, affidavits), see the section below.
Managing Your Saved Signatures
You can store multiple signatures, useful if you sign formally with your full name in some contexts and casually with initials in others.
- To add a new signature: Open any document in Markup → tap + → Signature → Add or Remove Signature → tap + to create a new one.
- To delete a saved signature: Follow the same path, then tap the red minus (-) icon next to the signature you want to remove.
You can save as many as you need. A good practice: keep one formal signature (full legal name) and one set of initials for multi-page documents.
Tips for a Cleaner Digital Signature
The quality of your digital signature matters more than people realize, a sloppy one on a legal document looks unprofessional and may raise questions. A few things that actually help:
- Use your index finger, not your thumb, you get more control and smoother lines
- Rotate your phone to landscape mode, the extra width makes a real difference
- Sign slowly and deliberately, faster doesn’t mean cleaner
- Use a stylus if you have one, any capacitive stylus works with Markup, not just Apple Pencil
- If the first attempt looks wrong, tap Clear and redo it, don’t settle
Troubleshooting: Common iPhone Signing Problems
Can’t find the Markup icon? Make sure the document is fully open, not just in preview mode. In Files, tap the document to expand it completely. Markup requires iOS 13 or later. If you’re on iOS 12 or below, update your device.
Document won’t let you sign it? The file may be password-protected or have editing restrictions set by the sender. Try opening it in Adobe Acrobat Reader, which can often bypass basic restrictions. If it’s a secured government form or fillable PDF, request an editable version from the sender.
Signature won’t save? Check your available storage under Settings → General → iPhone Storage. Low storage can block file saves. Also confirm you’re tapping Done after placing the signature — not just closing the app.
Can’t find where your signed document is saved? Check the Recent section in the Files app. If you signed an email attachment, your reply will include the signed document in your Sent folder. For scanned documents, look under On My iPhone in the Files app.
When You Need More Than a Signature: Understanding Notarization
A regular electronic signature is legally valid for the vast majority of documents in the US, thanks to the ESIGN Act (2000), which gives e-signatures the same legal weight as handwritten ones. That covers NDAs, employment contracts, consent forms, invoices, rental agreements, and most business documents.
However, some documents require notarization, where a licensed notary public verifies your identity, witnesses the signing, and applies their official seal. Without notarization, these documents may be rejected by courts, government agencies, or financial institutions.
Documents that typically require notarization:
- Real estate deeds and mortgage documents
- Powers of attorney (financial and medical)
- Wills and living trusts
- Affidavits and sworn statements
- Vehicle title transfers
- Court filings and legal declarations
If your document falls into one of these categories, a signature alone, however it’s created, won’t be enough. You’ll need a notary.
Get Your iPhone Document Notarized Online
You don’t need to find a UPS store or bank branch. BlueNotary connects you with a licensed notary over a live video call, directly from your iPhone. The process takes about 15 minutes:
- Upload your document to BlueNotary
- Verify your identity (government ID + knowledge-based questions)
- Connect with a live, state-commissioned notary via video
- Sign while the notary witnesses the signing
- Receive your digitally notarized document with an official seal
BlueNotary is available 24/7 and accepted by courts, lenders, and government agencies across the country. It’s the same legal result as an in-person notarization, without the trip.
If you’re working with a power of attorney document, you can learn exactly how to sign as a POA, and when notarization is required, in our step-by-step guide.
For a broader look at which documents commonly require a notary seal, the most commonly notarized documents guide covers over 30 document types with state-specific requirements.
Quick Reference: Signing vs. Notarizing on iPhone
Need | Method | Tool |
|---|---|---|
Sign a PDF quickly | Markup tool | Built into iOS |
Fill out a form with fields | Fill & Sign | Adobe Acrobat (free) |
Send doc for others to sign | eSignature workflow | DocuSign or SignNow |
Notarize a power of attorney | Remote online notarization | BlueNotary |
Notarize a real estate document | Remote online notarization | BlueNotary |
Get an affidavit notarized | Remote online notarization | BlueNotary |
Conclusion
Signing a document on an iPhone takes less than a minute using the built-in Markup tool, and it produces a legally valid signature for the vast majority of documents you’ll encounter. For form-heavy PDFs, Adobe Acrobat Reader fills the gap. For formal contracts with tracking, DocuSign works without a subscription.
The one situation where you need something more: documents that legally require a notary’s seal. For those, BlueNotary lets you complete the entire notarization from your iPhone in about 15 minutes, available any time, day or night. Questions before you get started? Reach the team at [email protected].
Frequently Asked Questions
Q: How do I sign a document on an iPhone for free? Use the Markup tool built into iOS, it’s completely free and pre-installed on every iPhone running iOS 13 or later. Open your document in Files, Mail, or Photos, tap the pen-tip icon (Markup), select + → Signature, draw your signature, and tap Done. No account or download required. Your signature saves automatically for future use.
Q: Is an iPhone electronic signature legally binding? Yes, for most documents. Under the federal ESIGN Act (2000) and the Uniform Electronic Transactions Act (UETA), electronic signatures carry the same legal weight as handwritten signatures across the US. The main exceptions are documents requiring notarization, like real estate deeds, wills, and powers of attorney, which need a licensed notary’s seal in addition to your signature.
Q: Do I need a specific app to sign documents on my iPhone? No, the native Markup tool handles basic signing without any downloads. Third-party apps like Adobe Acrobat Reader or DocuSign are useful when you need additional features: Acrobat for filling out form fields, DocuSign for sending documents to others and getting a digital audit trail. For notarized signatures, BlueNotary is available directly from your iPhone browser.
Q: How do I sign a Word document on an iPhone? The simplest route: open the Word file in the Microsoft Word iOS app or Pages, then export it as a PDF (tap Share → Export → PDF). Once saved as a PDF, open it in the Files app and sign using Markup. Alternatively, the Word app itself has a built-in Draw feature that lets you add a handwritten signature to any document without converting it first.
Q: Can I sign a document someone sent me over text? Yes. If they sent a photo of a document, open it in Photos → Edit → Markup icon → + → Signature. If they sent a PDF via iMessage, tap and hold the attachment and select Save to Files. Then open it in the Files app and sign with Markup. Either way, you can sign without leaving your iPhone and send it back the same way it came.
Q: How do I sign and return a document by email on iPhone? Open the email in Mail, tap the attachment to open it, then tap the Markup icon. Add your signature, position it, and tap Done. Tap Reply, the signed document attaches automatically. You don’t need to save, export, or re-attach anything. The entire process takes under a minute from inbox to sent folder.
