Guide
How to sign a scanned document
Short answer
Scan the paper with your phone (Notes or Files on iPhone, the Scan button in Google Drive on Android), save it as a PDF, then add your signature in Markup, Preview or Acrobat Reader. To have someone else sign it, upload the scan to Sign PDF: we read the printed text, place signature and date boxes on the right lines, and send it for signing.
Updated 25 October 2026
Step by step
- 1
Scan the pages
iPhone: Notes or Files, Scan Documents. Android: Google Drive, plus button, Scan.
- 2
Save as PDF
Both apps save the scan as a PDF. Check every page is straight and readable.
- 3
Upload it
Upload the PDF scan, or a JPG, PNG or WebP photo of a one-page document, to Sign PDF. HEIC needs exporting as JPEG first.
- 4
Check the boxes
We place signature and date boxes from the printed text. Drag any that sit off the line.
- 5
Add signers and send
Enter names and emails. Each person signs in the browser after confirming a code.
- 6
Keep the sealed PDF
Store the completed file with its certificate. It replaces the paper for most purposes.
Scanning with the phone you already have
You do not need a scanner. On iPhone, open the Notes app, tap the attachment button and choose Scan Documents, or in the Files app tap the More button and choose Scan Documents. Hold the phone over each page; it detects edges and captures automatically. Tap Save, and Files stores a PDF.
On Android, open Google Drive, tap the plus button (or the camera shortcut) and choose Scan. Drive crops and straightens each page and saves a PDF to Drive. Google refreshed the Drive scanning screens in 2025, so the buttons may look slightly different on your phone.
For the cleanest result, lay the page on a dark, flat surface in good daylight and avoid shadows from your hand or phone.
Signing the scan yourself
Once you have a PDF, it signs like any other: Markup on iPhone (Add button, Add Signature), Preview on Mac (Sign), Acrobat Reader's Fill & Sign, or Edge's Draw on Windows. A scanned page has no fillable fields, so add the date and any typed answers with a text box.
Do not print the signed scan and scan it again. Each generation loses quality, and the signature becomes part of a fuzzy image.
Getting someone else to sign a paper document
Say you have a printed contract from a supplier, or an old form you need a client to sign. Scan it into a single PDF and upload that to Sign PDF. A one-page document can also go in as a photo: we accept JPG, PNG and WebP and turn the image into a PDF. We take one file per document, so for several pages, scan them together into one PDF first.
We read the printed words on the page, so if the scan says 'Signature of Client' or 'Date', we place the boxes on those lines and assign them. On faint or skewed scans, check the placement carefully and drag boxes where needed. iPhone photos in HEIC format are not supported yet; set the camera to Most Compatible, or export the photo as JPEG first.
Add the signer's email and send. They sign in the browser, and the finished PDF is sealed and carries the certificate of completion. The scan becomes a proper signed record rather than a picture of a picture.
Is a signed scan as good as the original?
For most contracts, a scanned or electronically signed copy is accepted. Some documents need the original wet-ink paper: wills, some deeds and property transfers, and documents for certain courts or registries. If an organisation asks for 'the original', a scan will not satisfy them. When in doubt, ask them or a lawyer. This is not legal advice.
Questions people ask
Can I sign a document that was scanned as an image?
Yes. Convert it to PDF with your phone's scanner, or for a single page upload the JPG or PNG to Sign PDF, which turns it into a PDF.
Why can't I upload iPhone photos?
Sign PDF does not read HEIC files yet. In Photos, share the image and choose a JPEG option, or set Settings > Camera > Formats to Most Compatible.
Does Sign PDF place boxes on scanned documents?
Yes. We read the printed text on the scan to find signature, name and date lines. On poor-quality scans, check placement and adjust it by dragging.
Is a scanned signature legally valid?
For most ordinary contracts, yes. Some documents require original wet-ink signatures. This is general information, not legal advice.
Upload a document and watch the boxes land
See every signature, initial and date box placed before you sign up. Sending starts at $5 a month, monthly, cancel any time.
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