Method 1: Digital signature with certificate authority
The most legitimate way to digitally sign a Microsoft Excel document (file) is with an official digital certificate.
What is a digital signature in Excel?
A digital signature, also known as a digital ID signature, or an e-signature, is an encrypted stamp of authentication. It confirms that the document and its contents come from the signer and haven’t been altered by someone else.
As you can see from the example above, after the Excel file has been digitally signed, editing is discouraged (although not entirely impossible).
This electronic signature helps validate the identity of the signer and the validity of the content.
With Excel, you can insert a signature line and sign it as well for free. But if you want to make it even more legit and authentic, you must obtain a signing certificate from a certificate authority.
Two certificate authorities that Microsoft recommends are:
Take note that digital certificates from these companies aren’t free.
Step 1: Insert a Microsoft Office signature line
To insert a Microsoft Office signature line in Excel, click on a cell where you want to place the signature line and head over to the ‘Insert’ tab.
Then, click the ‘Signature Line’ icon found on the ‘Text’ group.
Excel will then open a window for you to set up the signature line.
Step 2: Digital signature setup
Here, all you have to do is supply the information needed such as the signer’s name, suggested signer’s title, and email address.
You can also enter an instruction for the signer and allow the signer to add a comment in the signature setup dialog box.
Lastly, you could also show the sign date in the signature line.
Once you’re satisfied with the setup, click on the ‘OK’ button to insert the signature line.
Here’s how the signature line looks now:
Pretty cool, right?😎
Digitally sign the document
To sign the signature line, ensure first that the data on the spreadsheet is ready and there’s nothing you or the signer has to change.
1. Once you confirm that there’s nothing you have to edit, double-click on the signature line until an Excel ‘Sign’ window will show up.
2. Here, you can either type your name on the signature line (if you’re the signer of course) or insert a picture to use as the signature.
3. You can also add additional details by clicking on the ‘Details…’ box.
4. Once you’re satisfied, click on the ‘Sign’ box.
Here’s how it looks now:
Wasn’t that hard, eh?😉
Remove certificate signature lines
If you don’t want your signature line there anymore, you just left-click it and delete it like any other object – if it’s not signed, that is.
If it is signed, you need to right-click it and click ‘Remove signature’.
Invisible digital signature
If you have your Microsoft Office signature certificate you can add invisible digital signatures quite easily.
1. Go to the ‘File’ tab.
2. Click on ‘Info.
3. Click on the ‘Protect workbook’ drop-down list
4. Choose ‘Add a Digital Signature’.
This “invisible” signature isn’t visible within a specific sheet like the previous one.
And it does require a signing certificate like the visible ones.