How to scan and sign documents with your phone, and what the signed scan proves

To scan and sign documents with nothing but a phone, use the scanner it already has: Notes or Files on an iPhone, Google Drive or the camera on many Android phones. Save the scan as a PDF, read it, add your signature with the phone's markup or pen tool, and send it.

That's the whole job when you're the only one signing. If someone else has to sign too, upload the scanned PDF to a signing service instead, so each signer gets a link and you get a record. Chaindoc, which runs in your phone's browser, works that way.

If you want to scan and sign documents without installing anything, an iPhone already has both halves. Apple put the scanner in two places, and both make a PDF. Here's how to scan a document on iPhone, following Apple's own guide for iOS 26.

In Notes

1. 1.
   Open a note and tap the Attachment button (the paperclip).
2. 2.
   Tap Scan Documents and hold the phone over the page.
3. 3.
   In Auto mode the scan takes itself; otherwise tap the shutter or press a volume button.
4. 4.
   Drag the corners if they're off, tap Keep Scan, then add more pages or tap Done.

In Files

Tap the More button, then Scan Documents, and capture the pages the same way. Files asks where to put the PDF before you tap Save, which is handy when the document belongs in a shared folder rather than inside a note.

iOS 26 adds a flash toggle and image filters to both. Leave the flash off for glossy paper.

Scan and sign in Notes

Notes signs in place: open the scan, tap Markup, tap Add, then Signature, and drop it on the line. That's how to sign a scanned document on iPhone without another app. For a PDF that arrived by email rather than off your desk, read how to sign a document on your phone, which covers Markup in Mail and Files.

One quirk worth knowing: a scan made in Notes lives inside the note. If you'll be emailing it as a file, scanning in Files from the start saves a step.

Android has no single built-in scanner, but nearly every Android phone has Google Drive, and that's the easiest answer to how to scan a document on Android.

Google Drive

Open the Drive app and tap Camera at the bottom right. A blue outline shows where the picture will be cropped; shoot in Auto or Manual. Before you save, Drive lets you crop and rotate, apply a filter (grayscale is the one for text), clean off stains and stray fingers, and add pages. Then name the file, choose .pdf rather than .jpg, and tap Save. The steps are on Google's Drive help page.

The PDF lands in Drive, not on the phone. Convenient for sending a link. Less so for a passport scan you'd rather not keep in the cloud.

Samsung Galaxy camera

On Galaxy phones the camera does the job. In Camera settings, under Intelligent features, turn on Scan documents and text. A scan button then appears when the lens sees a page, and Auto scanning skips even that tap. Samsung says the settings vary by model, so if you can't find it, Drive still works.

Signing the scan

Drive covers the scanning. To scan and sign a document in one sitting, open the PDF in Drive and use the annotate pen, or use the Edit and pen tools in Files by Google and save a copy. Back at a laptop later? Here's every other way to sign a PDF.

Honestly, for a one-off you don't need a scanner app. The built-in tools above make a clean PDF. Apps earn their place when you scan a lot, want the text searchable, or want the scan to drop straight into a signing workflow.

• Adobe Scan turns camera shots into PDFs and runs text recognition (OCR) on them, so the scan becomes searchable. For signing, Adobe's own page sends you elsewhere: open the scan in Acrobat to fill and sign it. It needs iOS 15 or Android 8.0 and later.
• The DocuSign mobile app goes the other way. Its product page says you can scan and sign documents with your device's camera and collect signatures from your phone, so the scanner is a side door into its signing service.
• Microsoft's OneDrive app has a scanner too (tap +, then Scan photo), and it's the route Microsoft now recommends because Microsoft Lens is gone. Lens left the App Store and Google Play on February 9, 2026 and stopped making new scans on March 9. Plenty of older guides still recommend it.
• CamScanner is popular and has a history worth knowing. In August 2019 Kaspersky found a malicious module in its Android app, which had over 100 million installs, and Google removed it from Google Play after the report.

That last point isn't really about one app. A scanner app sees every page you feed it: leases, IDs, bank letters. Before you hand one your paperwork, check where it keeps scans and whether it wants an account. For anything sensitive, the scanner that came with your phone is the safer default.

So which app to scan and sign documents should you pick? If you're the only signer, nothing beyond what's on the phone. If other people need to sign, choose a signing service and treat its scanner as a convenience.

Before you scan and sign documents that matter, get the capture right. Knowing how to scan a document with your phone is the easy half. Getting a scan you can sign and send without a reply asking for a better copy takes a few habits.

• Light from the side, not from above. Your own shadow is the most common smudge on a phone scan.
• A dark, plain surface under white paper helps the scanner find the edges.
• All four corners in frame, phone parallel to the page. A tilted shot crops the margin, and margins hold page numbers and initials.
• Grayscale or black-and-white for text. Color only when the page has a stamp, a signature in blue ink or a highlighted clause you'll want to point at later.
• One PDF, every page, in order. A pile of JPGs is an invitation to lose page 4.
• Mind the file size. Gmail stops attachments at 25 MB on a personal account and turns anything larger into a Drive link. A long color scan can blow past that; grayscale usually brings it back.
• Name it for the person who'll search for it next year. That's probably you.

All five ways to scan and sign documents below end with a signed page on your phone. What differs is what anyone can prove about that signature a year from now, which is the column worth reading first.

Usually, yes, and the scan matters less than people fear. But "a signed scan" can mean two different things, and the law treats them differently.

The first: you scan and sign a document on the phone itself. In the US, section 106(5) of the ESIGN Act defines an electronic signature as an electronic sound, symbol or process attached to a record and adopted with the intent to sign it, and section 101(a) says a signature or contract can't be denied legal effect solely because it's electronic. A signature you draw with your finger on a scanned PDF fits that definition. Most states add the same rule through their own versions of UETA. In the EU, Article 25(1) of eIDAS says an electronic signature can't be refused legal effect or admission as evidence just because it's electronic or isn't qualified. What you've made is a simple electronic signature: valid, but carrying no evidence of who drew it unless a signing service recorded that at the time.

The second is a paper page you signed in ink and then scanned. Here the scan is a copy. The Federal Rules of Evidence call it a duplicate, a counterpart made by a photographic or electronic process that accurately reproduces the original (Rule 1001(e)), and Rule 1003 admits a duplicate to the same extent as the original unless someone raises a genuine question about the original's authenticity or admitting the copy would be unfair. Notice the escape hatch. If the other side says the signature isn't theirs, everyone goes looking for the paper. Keep it.

Scan quality turns out to be a legal point too. Where a law requires you to keep a record, ESIGN section 101(d)(1) accepts an electronic copy only if it accurately reflects the information in the original and can be accurately reproduced later. A scan with a clipped margin or an unreadable clause doesn't clearly do that.

Some documents sit outside these rules altogether. ESIGN section 103 excludes wills, codicils and testamentary trusts, family-law matters such as adoption and divorce, court documents, and several consumer notices, foreclosure and eviction among them. Lenders, county recorders and notaries also set their own rules. Before you scan and sign one of those, read when a wet ink signature is still the safer choice.

You can, and plenty of people do: snap the page, open the photo in a markup tool, sign. Legally it's the same simple electronic signature as a signed scan. In practice it's worse. A photo comes out skewed and shadowed, the margins wander, it's saved as a JPG, and the other side may write back asking for a proper copy. If the paper's still within reach, scan it again with Notes or Drive; both straighten the page and save a PDF.

Everything so far assumes you scan and sign documents for yourself alone. Once a second person has to sign, emailing a marked-up PDF around gets messy: they draw on your copy, send it back, and nobody can say later who signed which version, or when.

A signing service fixes that. In Chaindoc, which works in your phone's browser (its own iOS and Android apps are still in development and not in the stores), you upload the scanned PDF and send the document for signature to up to 10 people. The server hashes the file the moment you upload it. When you publish it for signing, that version's hash goes on a blockchain, and each signer's proof is recorded when signing completes, so a page swapped in later shows up as a mismatch. Everyone gets their link at once; a fixed signing order comes with approval routes on the Business plan. ID checks (KYC) are available on paid plans when a deal calls for them, never required.

When the last person signs, you download the completed PDF with its audit trail, and the signed file can be checked later through a verification service for signed PDFs. The Free plan covers 5 signatures a month without a card; Chaindoc's plans list the rest.

Each of these takes seconds to avoid and weeks to untangle.

• Signing before you've read the scan. The paper and the scan aren't always the same document; a crop can drop a line.
• Sending a stack of JPGs instead of one PDF.
• Shredding the original. Keep the paper at least as long as the scan, and check how long to keep signed records for your kind of document.
• Scanning ID cards or bank letters with an app you haven't looked into.
• Overwriting the unsigned scan. Save the signed version as a copy, so you can show what you were asked to sign.
• Using a scan where the law wants ink or a notary. Wills and family-law papers are the usual cases.

None of this needs special software. It needs thirty seconds of care at the moment you scan and sign documents, which is exactly when you're in a hurry.