Glossary
What is the code sent to your phone
The most common second factor when signing, and why it adds so much.
One-time code
A short number, valid for a few minutes and only once, sent to a channel only the signer controls — usually their phone — to check they are who they claim to be.
It does the same job as asking for ID at a counter: checking that the person in front of you is who they say. Only here, what is checked is access to a specific phone number.
Why it adds so much
It is the difference between "someone with access to this inbox accepted" and "the person holding this phone accepted". In a dispute, the second sentence is far harder to argue with.
Watch out
Never share that code with anyone, not even whoever sent you the document. No legitimate party will ask for it by phone: the code is yours and is typed into the screen, not dictated.
Worth knowing
If it does not arrive, request another. Requesting another does not invalidate the document or force you to start again.
›How long does it last?
A few minutes. After that you request a new one.
›Does receiving it cost anything?
Not for the signer.
›What if I no longer have that number?
Tell whoever sent the document so they can update the contact.
A real case
The situation
Someone receives a call asking for the code that just arrived on their phone.
What you do
- Does not give it
- Warns the company that sent the document
What you get
Prevents a third party signing in their name; the code was the only piece the caller was missing.
The situation
A signer does not receive the code and cannot sign.
What you do
- Checks the registered number and resends
What you get
The blockage clears without changing the document.
The situation
The code is shared with a colleague so they can sign instead.
What you do
- Explains the signature will stand in the name of whoever received the code
What you get
Each signature still points to one specific person.
The situation
A mobile number is mistyped in the contact record.
What you do
- Corrects the contact before resending the request
What you get
The code reaches whoever has to sign.
The situation
Somebody phones asking for the code, posing as support.
What you do
- It is not given and whoever sent the document is alerted
What you get
An attempt to sign in someone else's name is stopped.
The situation
A signer with no signal cannot receive the message.
What you do
- Agrees another verification route with whoever sent it
What you get
The signature is resolved without giving up the second factor.
This article answers
- what is a one-time code
- what is the code sent when signing for
- the one-time code is not arriving
- sms verification when signing