Open the Excel document needing a signature if it's not open already. Then open the "Sign" dialog box by either double-clicking the signature line or by right-clicking it and selecting "Sign." Add ...

Create a Digital Signature in Excel First things first, to create a digital signature, you must have a signing certificate, which proves identity and verifies the authenticity of the document.

You can add a signature to an Excel spreadsheet using electronic signature software or using the Insert feature in Excel. Open an Excel spreadsheet and select Insert > Add a Signature Line.

How to Add a Signature Line in Microsoft Office. Asking people who read your Microsoft Office Word documents to sign on the bottom line is never a problem when the page is printed out.