On iPhone, open the PDF in Files, tap Markup, add a signature, place it on the page, then tap Done to save it.
A contract can sit in your inbox for hours before the built-in Markup tool makes how to e-sign a PDF on iPhone a one-minute task. You do not need to print, scan, or buy a signing app for a normal approval form.
The built-in signature works when the sender accepts an electronic signature image placed on the PDF. If the sender requires a certificate-based digital signature, use the signing service they named, because Markup does not add a cryptographic certificate or audit trail.
E-Signing A PDF On iPhone In The Files App
The Files app is the most reliable place to sign a saved PDF because the edited file stays on your iPhone or in iCloud Drive. The same Markup signature tool can handle forms from Mail, Messages, Safari, and AirDrop after the PDF is saved.
- Open Files.
- Tap Browse, then open the folder that holds the PDF.
- Tap the PDF once to open the preview.
- Tap the Markup button, the pen-tip icon usually near the bottom or top edge of the preview.
- In the Markup toolbar, tap the Add button, then tap Add Signature.
- Sign with your finger, tap Done, then drag the signature onto the signature line.
- Resize the signature by dragging any dot on its outline.
- Tap Done to save the signed PDF.
The PDF returns to the Files preview with your signature visible on the page. Reopen the file once before sending it if the document matters, since that confirms the edit was written into the saved PDF.
Fill Blank Fields Before The Signature
A form should be filled before the signature is placed, since moving a signature later can cover typed text or checkboxes. Markup can add typed boxes, handwritten marks, initials, and a full signature in the same editing session.
Tap any fillable field first if the PDF supports form fields. For a flat PDF that has no tappable fields, use Add, then Add Text, drag the box into place, and type the missing information.
Use initials only where the document asks for initials. A saved initials signature helps with rental forms, school forms, and short approvals that have several small signing spots.
If you need an unchanged original, keep the first download in a separate folder before editing. That leaves one blank copy and one signed copy.
Match The iPhone PDF Signing Method To The File
Different starting points need slightly different handling, but Markup is still the core tool for a normal PDF signature. Use the table to pick the shortest path from the app where the PDF arrived.
| Where The PDF Starts | Use This Method | When It Helps |
|---|---|---|
| Files app | Open PDF, tap Markup, tap Add Signature | Contracts and forms already saved on iPhone |
| Mail attachment | Open the attachment, tap Markup, sign, then send | Replying to a sender with the signed copy |
| Safari web PDF | Tap Share, choose Save to Files, then sign in Files | Web forms that open in the browser |
| Messages file | Open the file or save it to Files, then use Markup | One-off forms sent by text |
| Paper document | Scan in Notes, save as PDF, then add a signature | Turning a paper form into a signed PDF |
| Many initials needed | Create saved signatures for full name and initials | Forms with several signing spots |
| Locked PDF | Ask for an editable copy or a signing link | Files that block Markup edits |
| Certificate required | Use the sender’s signing service | Business forms that need identity records |
Where Is The Signature Tool On iPhone?
The signature tool sits inside Markup, not in a separate signing app. Apple’s iPhone User Guide describes adding a signature with Markup by tapping Markup, tapping Add, choosing Add Signature, signing with a finger, and tapping Done.
The Add button may appear as a plus sign in the Markup toolbar. After you create a signature, iPhone saves it, so the next PDF can use the same signature without drawing it again.
Saved signatures can include a full name, nickname, or initials. To manage them, open Markup, tap Add, tap Add Signature, then choose Add or Remove Signature.
Sign A PDF From Mail Or Safari
Mail works well when you need to reply with the signed attachment, while Safari usually works better after the PDF is saved to Files. Saving first prevents the browser preview from closing before the edit is finished.
For Mail, open the PDF attachment, tap Markup, add the signature, then tap Done. Mail should return you to the message flow with the marked-up attachment ready to send.
For Safari, open the PDF, tap Share, choose Save to Files, pick a folder, then open that saved copy in Files. After signing, tap Share if you need to email or message the finished PDF.
Why Won’t The Signature Save?
A signature usually fails to save because the PDF is locked, the file is still in a browser preview, or Done was not tapped after placing the signature. The fix is to get the PDF into Files, finish Markup, and reopen the saved copy before sending.
| Problem | What To Do | What Changes |
|---|---|---|
| Markup is missing | Tap the screen once, or save the PDF to Files | The pen-tip tool appears in the PDF preview |
| Add Signature is missing | Tap Add in the Markup toolbar | The signature menu opens |
| Signature looks too large | Drag a dot on the outline inward | The signature fits the line |
| PDF will not edit | Ask the sender for an unlocked PDF or signing link | The form can be completed without breaking permissions |
| Browser loses the edit | Use Share and Save to Files before signing | The signed copy stays on the device |
| Email sends the old file | Open the signed PDF in Files, then tap Share | The visible signed version becomes the attachment |
Send The Signed PDF Without Losing The Edit
The final check is simple: reopen the signed PDF, make sure the signature is visible, then share that exact file. Do this before deleting the original message or browser tab.
- Open the signed PDF from Files.
- Zoom in on the signature line and check placement.
- Tap Share.
- Choose Mail, Messages, or AirDrop.
- Add the recipient and send the PDF.
- Open the sent attachment from your message history if the form is time-sensitive.
A visible signature after reopening is the sign that the PDF saved correctly. For everyday forms, that is all most senders need; for identity-verified paperwork, follow the sender’s signing link instead.
References & Sources
- Apple.“Fill out forms, sign documents, and create signatures iPhone.”Shows the current iPhone steps for adding a signature to a document with Markup.