How to Add a Digital Signature to Your Excel Workbook

Have you ever needed to share an important Excel file with someone else but worried about whether it might be tampered with or modified without your knowledge? Don’t worry; you can add a digital signature to your Excel workbook to make sure it remains secure and authentic.

For example, imagine you are a freelancer and audited a few financial documents or created a sample quote for a specific service. Now, you want to send that Excel file to your new client, but you also want to make sure that they receive the exact same version of the file that you created. By adding a digital signature to your Excel file, you can authenticate the file and ensure that it remains unmodified.

In this article, I will show you how to add a digital signature to your Excel file in a few simple steps so that you can share your work with confidence.

Table of contents:

1. What is a digital signature?
2. How to add a digital signature to an Excel file
3. How to add an invisible signature to your Excel file
4. How to remove a digital signature in Excel
5. Conclusion

What is a Digital Signature?

A digital signature is like an electronic and encrypted seal that can be added to a document, an Excel file in this case, to show that it hasn’t been altered or tampered with. It’s an easy way to ensure that the document is authentic and came from the person who claims to have created it.

When you digitally sign a document, MS Office or any other signing software uses a specific method to generate a code based on the contents of the file. This code is then encrypted and added to the digital signature. Any modification to the document, however small it is, will destroy the digital signature.

The software automatically checks the signature when someone tries to open a digitally signed document. If the signature is valid, the document is authentic and unmodified. If the document’s content is modified in any way, the digital signature will not match, and you will be shown an alert message in such cases.

How to Add a Digital Signature to an Excel File

Signing an Excel file is similar to signing a Word document and just as easy. This is because of the UI (User Interface). Follow the below steps to add a digital signature to an Excel file.

1. Open the Excel file you want to sign.
2. Click on the Insert tab.
3. Select Signature Line from the Text menu.
4. Fill in the following fields with related information.
   1. Suggested signer
   2. Suggested signer’s title
   3. Suggested signer’s email address
   4. Instructions to the signer
5. Press the Ok button.
6. This will add the signature box to your Excel file.
7. Double-click on the signature box.
8. Add the signature in the blank field.
9. To add an image signature, click the Select Image link.
10. Click the Sign button after adding the signature.
11. Click the “Ok” button in the confirmation prompt.
12. With that, you’ve added the digital signature to Excel.

First of all, open the Excel file you want to digitally sign. After that, go to the “Insert” tab, click on the “Text” menu, and select the “Signature Line” option.

This will open the Signature Setup window. Here, fill in the following fields with relevant information. Once done, click the “Ok” button.

1. Suggested signer: Preferably your name.
2. Suggested signer’s title: Your official title, if any.
3. Suggested signer’s email address: Your preferred email address.
4. Instructions to the signer: Specific instructions you want to see when signing the Excel file.

The above action will add the signature box to your Excel file. You can click, hold, and drag it to make sure it is in the right place. Once you sign the Excel file, you cannot move the signature box. So, make sure it is in the right place before signing.

Next, double-click on the signature box. It will show you the add signature box. Here, type your signature in the blank field. To add an image signature, click the “Select Image” link.

Select the image you want to add as the signature and click the “Select” button.

Once the signature is added to the box, click the “Sign” button.

Click the “Ok” button when prompted.

As soon as you do that, the digital signature is added to the Excel file.

Once added, you will see the “Marked as Final” and “Signatures” notifications at the top of the file. From now on, the Excel document will open in Read-Only mode and doesn’t allow any changes to the document.

That is it. It is that simple to add a visible signature to your Excel workbook.

How to Add an Invisible Signature to Your Excel File

You can also add an invisible signature to your Excel file. This is particularly helpful if you don’t want the signature to appear in the workbook but want to authenticate and protect it from modifications. The process is very similar to how you password-protect an Excel file.

Here’s how to add an invisible signature to your Excel file:

1. Open the Excel file you want to sign.
2. Click on the File option at the top.
3. Go to the Info tab on the sidebar.
4. Click on the Protect Workbook dropdown menu.
5. Select the Add a Digital Signature option.
6. Select an option from the Commitment Type dropdown.
7. Type a purpose in the second field.
8. Click the Sign button.
9. Click the Ok button in the confirmation prompt.
10. With that, the Excel file is digitally signed with an invisible signature.

Open the Excel file. After opening it, click the “File” option at the top.

Next, go to the “Info” tab. Here, click on the “Protect Workbook” dropdown menu and select the “Add a Digital Signature” option.

The above action will open the Sign config window. Here, filling the “Commitment Type” and “Purpose” fields and click the “Sign” button. If you want to add more details to the signature, click the “Details” button and add the relevant details.

Finally, click the “Ok” button.

That is it. With that, the Excel document is digitally signed. From now on, the Excel document will open in Read-Only mode and doesn’t allow any changes to the document.

Since this is an invisible signature, you will not see any signature box in the worksheet. However, you will see the “Marked as Final” and “Signatures” notifications at the top of the file to indicate that the Excel workbook is signed.

How to Remove a Digital Signature in Excel

You can use the Remove Signature option to remove a digital signature in an Excel file. This is especially useful if you want to modify or re-sign the document.

Here’s how to remove a digital signature in Excel:

1. Open the digitally signed Excel file.
2. Click on the View Signatures button at the top.
3. Click the dropdown menu under valid signatures.
4. Select the Remove Signature.
5. Click Yes in the warning prompt.
6. Press the Ok button in the confirmation prompt.
7. The digital signature is removed.
8. You can delete the signature box if it is visible.
9. Finally, save the Excel file.
10. With that, you’ve successfully removed the digital signature in Excel.

Digitally Signing Excel — Conclusion

As you can see, it is quite easy to insert a signature in Excel.

A digital signature is a simple way to authenticate and secure your documents. It provides you with peace of mind when sharing important files with others.

You can either add a visible signature or an invisible signature. Depending on your use case, add the required one. No matter which kind of digital signature you add, it will work the same.

Of course, when you no longer need it, you can follow the steps shown above to remove the digital signature in Excel.

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That is all. It is that simple to insert a digital signature in Excel.

I hope this simple and easy Windows how-to guide helped you.

If you are stuck or need help, email me, and I will try to help as much as possible.

If you like this article, check out how to create a self-signed digital certificate in MS Office.