Ref: Integrating Docusign with Excel | Community

I submit this idea as I see it as a significant limitation of DocuSign platform.

Just copying what I wrote on referenced link above :

I’ve been surprised that Docusign cannot craft digitally signed file without converting to PDF. The fact that it is PDF comes I suppose from globaly recognised PDF standard also indicated as best-in-use by auditors and legal. 

Excel signed file is not less secured though (!) and additionally assures full functionality of Excel including full  Excel-like visibility and readability and navigation thru it after it is signed. 

Please consider to add an option (!) in Docusign to sign Excel files; better - all MS Office or other files’ types -  for digital signature.

Conclusion : PDF files and Excel (or any other files) digitally signed have exactly same security features:

Authenticity, Integrity and Non-repudiation.

Hence why not to give users this option and let them decide which files’ types they would like to sign.

Boguslaw