The most common reason anyone still sends a fax is a signature. An insurer, a lender, a doctor's office, or a government agency sends you a PDF, asks you to sign it, and wants it back by fax. The old way was print, sign, scan, walk to a fax machine.

You can skip most of that. Every phone and computer now ships with a free way to sign a PDF, and a fax goes out from a browser tab. Here is how to sign and fax a PDF on each device — and the one question to answer first, because some recipients still insist on ink.

  • Check first: drawn signature or ink?
  • Free, built-in signing tools on Mac, iPhone, iPad, Windows, Chromebook, and Android
  • Making the signature survive fax resolution

Table of Contents

First: is a drawn signature acceptable?

A signature drawn on a PDF with a trackpad or stylus is an electronic signature. For a great many documents — consent forms, account changes, routine business paperwork — recipients take it without a second look.

Some forms and organisations require a handwritten ("wet ink") signature, and a few government forms have their own specific rules about electronic signatures. The only reliable answer is the form's instructions or the person asking for it. If they say "sign in ink" or "original signature," print, sign, and scan. If they say nothing, a drawn signature is normally fine. If the stakes are high, ask.

Either way, the signed document ends up as a PDF, and the fax step is the same.

Sign on a Mac with Preview

Preview has had signature capture built in for years.

  1. Open the PDF in Preview.
  2. If the Markup toolbar is not visible, click the Show Markup Toolbar button.
  3. Click the Sign button.
  4. Create your signature using the trackpad (sign with a finger), the camera (sign on white paper and hold it up to the camera), or a nearby iPhone or iPad.
  5. Click the saved signature to drop it on the page, then drag it onto the signature line and resize it from the corners.
  6. Save the file (Command-S).

Preview keeps your signatures for next time. Use the text tool in the same toolbar to type the date or fill in fields that are not fillable. Then fax it from Safari — see faxing from a Mac.

Sign on an iPhone or iPad with Markup

  1. Open the PDF in the Files app. (From Mail, touch and hold the attachment and save it to Files first.)
  2. Tap the Markup button (a pen tip icon).
  3. Tap +, then Add Signature.
  4. Sign with your finger — or Apple Pencil on iPad — and tap Done.
  5. Drag the signature onto the line, resize it, and tap Done to save.

Markup can store more than one signature, such as a full signature and initials. The edits are saved into the file, so if you might need the unsigned version again, duplicate it first. Full phone-side steps are in our iPhone and iPad guides.

Sign on Windows (or anywhere) with Adobe Acrobat Reader

Windows has no Preview equivalent with a dedicated signature tool, but Adobe Acrobat Reader is free and available for Windows, Mac, iPhone, and Android.

  1. Open the PDF in Acrobat Reader.
  2. Choose the Fill & Sign tool.
  3. Choose to add a signature. You can type it, draw it, or upload an image of your handwritten signature.
  4. Click where the signature belongs, then adjust its size and position.
  5. Save the PDF.

Menu placement shifts between Reader versions, but the tool is consistently called Fill & Sign. Ignore the options to send the document for signature by others; you only need to sign it yourself and save it.

Microsoft Edge, which opens PDFs by default on Windows, also has a draw tool that works as a quick signature with a pen or touchscreen, though Reader gives a cleaner result with a mouse.

Sign on a Chromebook or Android

Chromebook: open the PDF from the Files app and it opens in the Gallery app. Google's help documentation says Gallery can fill in forms, add text, and let you draw and save a signature to reuse. Google is explicit that this is a convenience, not a verified electronic signature. See faxing from a Chromebook for the rest.

Android: the Google Drive app's PDF viewer has an annotate (pen) button that lets you draw on a PDF and save the changes or a copy. It works for a signature, though a fingertip signature on a phone screen is rarely elegant. Acrobat Reader's Fill & Sign on Android is the more polished option. Then fax it as described in our Android guide.

The print-sign-scan route

When ink is required, do it the old way — minus the fax machine.

  1. Print the page that needs signing.
  2. Sign in black or dark blue ink. Pencil and light blue often vanish at fax resolution.
  3. Scan it with your phone: Notes → Scan Documents on iPhone, the Drive app's scanner on Android, or the Camera app's document mode on a Chromebook.
  4. Use the scanner's black-and-white filter for contrast.

If only one page needs a signature, you can fax that scanned page together with the original PDF. Faxio accepts several PDFs in one fax, so the unsigned pages stay crisp and only the signed page is a scan.

Fax the signed PDF

  1. Open a fax service in your browser — on Faxio that is faxio.app/send.
  2. Upload the signed PDF. Faxio accepts PDFs only; add several files if your document is split.
  3. Choose the country and type the fax number.
  4. Add a subject for a cover page, so the signed form reaches the right desk.
  5. Send, and watch the status move from Sending to Delivered.

Before you send, open the signed PDF one more time. Make sure the signature landed on the right page, the date is filled in, and every page that needs initials has them. A missing signature is the classic reason faxed forms bounce back — our IRS fax guide covers how often that happens with tax forms.

What it costs

The signing tools above are free. Pay-per-fax pricing generally runs $2 to $5 per fax.

Faxio is $2.99 for a single fax of up to 10 pages, with no subscription, no account, and no card kept on file. If the transmission fails, the credit returns automatically. Packs bring it to $2.00 or $1.67 per fax, credits never expire, and an optional $14.99/month unlimited plan exists for people who fax weekly.

Signing and faxing a PDF is a two-tool job: the signature tool already on your device, and a browser tab. Check whether ink is required, sign, check the result, and send.

Fax your signed PDF →

Frequently asked questions

Can I sign a PDF and fax it without printing?

Yes. Sign the PDF on screen with a free tool such as Preview on a Mac, Markup on an iPhone or iPad, or Adobe Acrobat Reader, save it, and upload it to an online fax service. Nothing has to be printed unless the recipient specifically requires an ink signature.

Is a signature drawn on a PDF legally valid on a fax?

For many everyday documents, electronic signatures are widely accepted. Some forms and agencies require a handwritten signature, though, and only the recipient's instructions can tell you which applies. When the instructions say to sign in ink, print, sign, and scan.

How do I sign a PDF on my iPhone?

Open the PDF in the Files app, tap the Markup button, tap the plus button, and choose Add Signature. Draw your signature, tap Done, drag it into place, and tap Done again to save.

How do I sign a PDF on a Windows PC for free?

Adobe Acrobat Reader is free and includes a Fill & Sign tool that lets you type, draw, or upload an image of your signature and place it on the document. Save the file, then fax it.

Why does my signature look faint on the fax?

Fax is black and white at low resolution, so thin or light-coloured strokes break up. Use black ink or a black pen colour, make the signature larger, and avoid pasting a low-resolution photo of your signature.

How much does it cost to fax a signed PDF?

Signing with built-in tools is free. Pay-per-fax services generally charge $2 to $5 per fax; Faxio is $2.99 for a single fax of up to 10 pages, with no subscription and the credit returned automatically if the transmission fails.

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