How to sign a document with OTP verification
A signature link that anybody can open is a signature anybody can make. OTP verification closes that: before the document opens, a one-time password goes to the signer phone or inbox, and only the person holding it gets in. It is the cheapest identity control that actually changes what the audit trail is worth, and it takes one switch to turn on.
Send a document for OTP signing →
Drop your document here and sign it now. PDF, Word and Excel all work: a .docx or .xlsx is laid out in your browser exactly as it was written, so there is nothing to convert first. Add a signature, a date, a company stamp or a watermark, then download it sealed. Free to start, no account, and the file is never uploaded to open it.
How to sign a document with OTP verification, step by step
- Upload the document, Drop the PDF, Word or Excel file in. Word and Excel are laid out and drawn here, so there is nothing to export first.
- Add the signer and turn on verification, Enter the signer email or mobile number and switch on one-time password verification for that recipient.
- They receive a code, not just a link, The link arrives as usual, and the document will not open until the code sent separately is entered. A forwarded link on its own is useless.
- The code lands in the audit trail, The certificate records that the code was issued, when it was entered and from which device and IP, alongside the signature itself.
What you get
- A forwarded signing link stops being a way in, because the code goes to the signer rather than the link.
- The audit certificate records the verification, so the control is provable rather than just claimed.
- Works over SMS or email, so a signer with no smartphone is not locked out.
- Combines with full ID document checks where a transaction warrants more than an OTP.
- No subscription to switch it on.
Frequently asked questions
How do I sign a document with OTP?
Upload the document, add the signer, and switch on one-time password verification for them. They get the signing link as usual, and the document will not open until they enter the code sent separately to their phone or inbox.
Does an OTP make a signature legally binding?
What makes an electronic signature binding is the intent to sign plus evidence linking the signature to the signer, under the ESIGN Act, UETA, eIDAS or their local equivalent. An OTP is evidence of that link, and a strong one, but the requirements for a specific document type are set by the law that governs it. Check anything unusual before relying on it.
What is the difference between OTP and full ID verification?
An OTP proves control of a phone number or inbox. An ID document check proves who the person is, by reading the document and matching it to a live selfie. OTP suits everyday commercial documents; ID checks suit onboarding, lending, property and anything where the counterparty is a stranger.
Can the signer be verified without a smartphone?
Yes. The code can go by SMS to any mobile, or by email, and it is entered in the browser they already have open.
What if the code does not arrive?
It can be resent, and the resend is recorded in the audit trail as well, so nobody has to take a support conversation on trust.
What PDF Verified is, and what it is not
Electronic signature law is settled in broad terms and specific in the details. The ESIGN Act, UETA, eIDAS and their equivalents recognise electronic signatures across more than 190 countries, and what decides a particular case is intent to sign plus evidence connecting the signature to the signer, which is what the audit certificate records. Certain document types carry their own formalities wherever you are: deeds, wills, some property instruments, and anything requiring a witness or a notary. Sign only what you are authorised to sign, since applying another person signature without their authority is forgery whatever tool is used.
PDF Verified is a tool for preparing, signing, stamping and checking documents. It is not a law firm, a compliance service or a forensic examiner, and nothing here is legal, financial or compliance advice. Requirements differ by country, by document type and by the party asking, so check what applies to your document before you rely on it, and take advice where the document matters. You are responsible for the documents you create, sign and send, and for having the authority to do so: signing or stamping in somebody else name, or as an organisation you do not represent, is forgery whatever tool is used. To the extent the law allows, we accept no liability for how a document made with this tool is used or relied on. The full position is in our terms of service.