A walkthrough of how digital signing works, the difference between a free e-signature and a legally valid DSC signature, and exactly how to add one to your PDF.
Free tools like Adobe Fill & Sign, DocuSign's free tier, or a scanned signature image let you add what's called an e-signature, a visual mark that shows intent to sign, but carries limited legal weight and no cryptographic proof of who signed or whether the document was altered afterward.
A Class 3 Digital Signature Certificate (DSC) is different, it's issued by a government-licensed Certifying Authority, cryptographically tied to your verified identity, and legally recognized under India's IT Act, 2000. For anything filed with MCA, GST, Income Tax, or similar portals, a DSC signature is what's actually required, a scanned signature or free e-sign tool won't be accepted.
Once you have a Class 3 DSC loaded on a USB token, signing a PDF takes a few minutes in any PDF reader that supports certificate-based signing (Adobe Acrobat Reader is the most common).
Insert your Class 3 DSC token (Wd Proxkey, InnaIT, HypSecu, or similar) into a USB port and make sure the token drivers are installed.
Open the document you want to sign using Adobe Acrobat or Acrobat Reader, both support certificate-based signing.
Click Tools in the top menu, then select Certificates, then Digitally Sign.
Click and drag to select the area on the PDF where your signature should appear.
Adobe will detect your certificate from the connected token. Choose it, enter your token password/PIN when prompted, and click Sign.
Adobe will prompt you to save the signed file as a new PDF, your signature and a tamper-evident seal are now embedded in the document.
Everything above assumes you already have a Class 3 DSC on a USB token. If you don't, we can get you verified and issued the same day.
You can add a free e-signature (a visual mark) using tools like Adobe Fill & Sign, but a legally valid, government-recognized digital signature requires a Class 3 DSC on a USB token.
The free Adobe Acrobat Reader DC supports certificate-based signing with a DSC, you don't need the paid Pro version just to sign documents.
Yes, a PDF signed with a Class 3 DSC from a licensed Certifying Authority is accepted across MCA, GST, Income Tax, and other government portals that require digital signatures.
