School sends a permission slip as a PDF. The landlord sends a renewal. The clinic sends a consent form, and all three want it back signed by Friday.

The old routine was print, sign, scan, or photograph the page and hope it is readable. Nobody enjoys it, and half the households I know no longer own a working printer.

A phone can do the whole thing, and it does not cost anything. The steps for each device, along with a look at the free online tools, are collected in this guide to sign PDF free without a subscription.

On an iPhone or iPad

Open the attachment in Mail or save it to Files. Tap the Markup button, then the plus button, then Signature. Draw your name with a finger or an Apple Pencil, tap Done, and drag it onto the line. Save, then reply with the file attached.

The phone stores the signature, so the next form takes a few seconds.

On a home computer

A Mac opens the PDF in Preview. Click Show Markup Toolbar, then the Sign button, and draw on the trackpad or hold a signature written on paper up to the camera.

A Windows computer has nothing built in for this. The free Adobe Acrobat Reader adds a Fill and Sign tool that types or draws a signature and saves the file at no charge.

Small things that save a second round

Fill in the text fields before you sign, not after. Some forms lock once a signature is in place.

Check the file on the phone before you send it. Sometimes the signature shows on your screen and the school says the page arrived blank. That means it was added as a floating note rather than part of the page. Saving a flattened copy fixes it, and most signing tools have that option under a name like flatten or finalize.

Keep the signed copy in a folder of its own. Somebody will ask for it again in March.

One thing worth knowing

A signature drawn with a finger is a real signature for everyday paperwork. Courts and regulators in the US and Europe accept electronic signatures for ordinary agreements.

Some documents are excluded, and they are the serious ones: wills, adoption and divorce papers, court filings, certain legal notices. Those still go through the old channels, which is not a bad thing. The permission slip for the museum trip does not.