Scanned, Electronic or Certified Signature: What's the Difference?
"Sign and send it back" can mean a photo of an ink signature, a name typed onto a PDF, or a signature made with a smart card. All three are called signatures, but they aren't the same thing. Here are the differences, and when each one fits.
1. Scanned signature
Print, sign with a pen, scan or photograph, and send. It's the traditional way and still common.
Pros: everyone knows it, and it looks like your real signature.
Cons: you need a printer and a scanner, and the result is often a heavy file. A picture of a signature can also be copied onto another document, so as proof it's no stronger than a typed signature.
2. Visible signature on a PDF
Your name in a signature style, or a drawing of your signature, added to the file directly on a computer or phone. This is what Sign PDF does.
Pros: fast, no printer, a clean and small file.
Cons: like a scanned signature, it doesn't technically prove who signed or that the document wasn't changed afterwards. Its validity rests on the agreement between the parties and the surrounding record, like the email the document was sent with.
Good for: everyday documents between parties who agree to work this way. Leases, approvals, internal forms, delivery confirmations.
3. Certified electronic signature
Many countries' laws recognize several levels of electronic signature. The highest level relies on a digital certificate issued by an accredited provider, usually used with a smart card or a secure app. The signature is mathematically tied to the document, so any change after signing is detected.
Pros: strong proof of who signed and that the document is intact.
Cons: you need to obtain a certificate, usually for a fee, and use compatible software.
Good for: documents where the receiving organization explicitly requires it, like some government filings, certain legal documents and some financial institutions' systems.
Signing platforms
Dedicated e-signature services send the document to the signer, record when and from which device it was signed, and produce an audit trail. They sit in the middle: stronger than a visible signature because of the record, and easier than a certified signature. Businesses that sign many contracts usually use one.
How do you know which you need?
Ask whoever requested the signature. If they say "certified electronic signature" or "digital signature with a certificate", you need the third level. If they asked you to "sign and send it back", a visible signature on a PDF is fine in most cases. The guide to signing a lease online shows the process in practice.