How do I add a digital signature professionally in a PDF document?

Enabling digital signature in documents is not an exclusive feature of Adobe, one can enable digital signature in a document without using Adobe Reader DC using the following tools:

• PDF Documents:
  • Foxit PhantomPDF
  • Nitro PDF
  • Smallpdf
  • LibreOffice
  • DocuSign
  • HelloSign
• For Office Documents:
  • Microsoft Office
  • OpenOffice/LibreOffice

Some of the free open-source digital signature software that can stamp a signature onto the document and save it are as follows:

• JSign
• OpenSC
• Cryptomator
• LibreOffice
• PDF-Shuffle

Some of the best eSigning software for Dot net Application are as follows:

• Adobe Acrobat Sign
• DocuSign
• SignWell
• SignNow
• ESignatures.io

• To create a digital signature in Word, you can use the built-in feature.
• Go to Insert > Signature Line and follow the on-screen instruction to create digital signature.

You can use Adobe Acrobat. Follow the steps given below to insert a digital signature in a PDF:

• Open your document in Adobe Acrobat.
• Move to the Tools tab.
• Scroll down until you reach the Forms and Certificates section.
• Then, click on the Certificates dropdown menu.
• From the dropdown menu, choose the option Open.
• Now, a new set of options will appear.
• Click on the Digitally Sign option.
• A list of available digital signatures will appear.
• Select the signature.
• Click on the Continue button to proceed with the digital signing process.