In Excel: for a picture of a signature use Insert ▸ Pictures; for a verifiable one use Insert ▸ Text ▸ Signature Line ▸ Microsoft Office Signature Line, then right-click it ▸ Sign.
For a picture: crop the scan tightly, remove the white background with Picture Format ▸ Remove Background, then Insert ▸ Pictures and position it.
For a signature line: Insert ▸ Text ▸ Signature Line ▸ Microsoft Office Signature Line, fill in name, title and instructions.
To sign it: right-click the line ▸ Sign, then either type your name, select an image, or choose a certificate.
Without a certificate, create one with SELFCERT.EXE from the Office install folder — it will be trusted only on that machine.
Save as .xlsx; signatures do not survive a save to CSV or an export that rewrites the file.
What this does
Two entirely different things share the word. An IMAGE of a signature — a scan or a photo with the background removed — is decoration: it proves nothing, anyone can copy it out of the file, and it is what most people actually want for an internal form. A DIGITAL SIGNATURE is cryptographic: it binds the signature to the workbook contents using a certificate, so any later edit invalidates it visibly. That requires a certificate, either from a certificate authority or a self-signed one made with the SELFCERT tool that ships with Office, and self-signed certificates are trusted only on the machine that created them. Excel's Signature Line sits between the two: it inserts a signature placeholder with the signer's name and title, which can then be signed either with a certificate or by inserting an image. Note that signing a workbook marks it final — the file becomes read-only, and editing it removes the signature. The same idea underpins a lot of everyday Excel work, so the few minutes spent getting it right here pay back across every sheet you build afterwards. Treat it as a pattern, not a one-off, and it stops being something you look up and starts being something you reach for. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “insert electronic signature in excel”. Start on a copy or a tiny sample, keep the affected cells visible, and compare the result with the tool above before you touch the real workbook. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. The point is a layout choice that keeps the sheet readable and sortable, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
An approval sheet needing the manager's sign-off. Insert ▸ Text ▸ Signature Line ▸ enter name, title and instructions ▸ OK. Excel places an X-with-a-line block in the cell area. The manager right-clicks it ▸ Sign, selects their certificate (or picks an image of their signature), and Excel marks the workbook as final. Any subsequent edit shows the signature as invalid rather than silently keeping it. The distinction between a picture of a signature and a cryptographic one decides whether the file proves anything at all, and Excel presents both under the same menu word. A practical tip before you scale it up: build it once on a small block of test data, confirm the number against the tool on this page, and only then point it at your real sheet. That one habit catches almost every mistake while it is still cheap to fix, long before a wrong figure reaches a report or a colleague.
In Google Sheets
If you are in Google Sheets rather than Excel, the good news is that the formula shown here is identical and the workflow barely changes — menus sit across the top instead of in a ribbon, and a few function names differ slightly, but anything you build here moves across with little or no rework. The aim was to get you unstuck fast and leave you a little more capable than a copy-paste would. The answer is at the top, the tool proves it, and the detail above shows why it holds — so the next time a colleague asks, you can answer without reaching for search. The short version of “insert electronic signature in excel”: the answer is at the top of this page, the tool proves it on your own numbers, and the sections above explain why it holds so the next variation does not stump you. Excel rewards people who reference cells instead of typing values and who keep inputs separate from formulas, because that is what makes a result you can audit months later. Build it once, deliberately, with the live tool as a check, and you convert a one-off lookup into a reusable skill — which is the whole point of learning the why and not just the what.
Common mistakes
- Treating a pasted image as legally binding — it is a picture, extractable by anyone who opens the file.
- Editing the workbook after signing, which invalidates the signature (this is the feature working, not a fault).
- Distributing a workbook signed with a self-signed certificate and expecting recipients to see it as trusted.
- Floating the image over cells so it drifts when rows are resized; set Format Picture ▸ Properties ▸ Move and size with cells.
- Using Excel for a document that needs a real audit trail, where a PDF signing service is the right tool.
Frequently asked questions
How do I add a signature in Excel?
Insert ▸ Pictures for an image of one, or Insert ▸ Text ▸ Signature Line for a Microsoft Office Signature Line that can then be signed.
What is the difference between an image and a digital signature?
An image is decorative and copyable. A digital signature uses a certificate to bind the signature to the file contents, so any later edit shows as invalid.
Do I need a certificate?
Only for a true digital signature. You can make a self-signed one with SELFCERT.EXE from your Office folder, but other machines will not trust it.
Why can I no longer edit the workbook after signing?
Signing marks it as final and read-only. Removing the signature restores editing, and it must be re-signed afterwards.