Signing a PDF Online: Typed Signatures vs. Certificate-Based Digital Signatures
Not every signature is the same. Learn the difference between a visual signature on a PDF and a certificate-based digital signature, and when each one is appropriate.
Two very different things called "signing"
A visual signature is text or an image of your signature placed on a page. It works like signing a printed copy: it shows your intent, and many organisations accept it for routine paperwork. Sign PDF on FileBuddy adds this kind of signature, with your typed name, the date, and a signature line on the page you choose. You can also place an image of your handwritten signature with Add Image to PDF.
A certificate-based digital signature is different. It uses a digital certificate issued to you, often stored on a USB token or provided by a certified signing service, to attach cryptographic proof to the file. Anyone can then verify who signed the document and confirm that it has not been changed since. FileBuddy does not create this type of signature.
When a visual signature is usually fine
Visual signatures are widely used for internal approvals, rental and service forms, school and club paperwork, quotes and invoices, and letters. If an organisation asks you to "sign and return" a PDF and does not mention a certificate, a visual signature is often what they expect.
When you may need a certificate-based signature
Some filings require a certificate-based signature, for example certain tax returns, company registration documents, tenders, and some court or government submissions. The rules depend on your country and on the organisation receiving the document. If the instructions mention a digital signature certificate, a DSC, a USB token, or a qualified electronic signature, a visual signature will not be accepted.
When in doubt, ask the organisation which kind of signature they accept. It takes a minute and avoids a rejected submission.
Making a visual signature look its best
Sign on white paper with a dark pen, photograph or scan it, crop it closely, and save it as a PNG. Then use Add Image to PDF to place it, choosing the page and position. Keep the signature at a realistic size; an oversized signature looks unprofessional.
If the PDF is a form, fill in the fields first with Fill PDF Form. To stop the filled-in values from being changed later, use Flatten PDF after signing, which turns the form fields into ordinary page content.
Key Takeaways & Engineering Checklist
- A visual signature is a mark on the page, like signing a printed copy.
- A certificate-based digital signature is cryptographic proof of who signed and that the file has not changed since.
- Many everyday documents accept visual signatures; some legal, tax, and government filings require certificate-based ones.
- If you are unsure, ask the organisation that requested the signature.