If a signature is not validated in a PDF, we see Validity unknown with a question mark. You need to validate the signature to make it valid.

We show you how to sign digital documents on your PC or smartphone free of charge.

Learn how to manage PDFs for free with PDF Gear. Edit, sign, and convert files effortlessly without expensive software. Free PDF editing ...

Making PDF documents on Mac An easy way to make a PDF document on Apple Mac computers for free is printing, this is also available on PC computers as well.

Need to sign an e-mailed PDF document? Going through the motions of printing, signing, and scanning the document is tedious. Fortunately, there's a faster way to go about this process.

Tired of printing, signing and then scanning documents? Here are the simple steps to signing PDF and Word documents on your phone and computer.

Sometimes you need to sign or fill out PDF forms while you're away from your Mac. Here's how to get that paperwork done on your iPhone or iPad.

How to sign Word documents on your iPhone To sign a Word document, you'll need to save it to your iPhone and then open it in the Microsoft Word app (free for iOS).