English01Sign-up
Your YourApp code is 481920. Do not share it with anyone.
Confirm that a real person controls the number before an account is created.
Verify API
One-time passcodes that actually arrive
Verify sign-ups, logins and payments with a passcode sent to the user’s phone, over the channel most likely to reach them.
Verify · Sign-upIllustrative
Verification is the message users wait for
Built for speed
Passcodes are time-critical, so verification traffic should never sit behind a marketing blast.
More than one way in
Reach users by SMS, with WhatsApp or voice available when SMS is not the best route.
Fewer fake sign-ups
Confirm that a real person controls the number before an account is created.
See what happens
Track delivery for every passcode so you can spot drop-offs in your sign-up flow.
How verification works
Create your account
+1 415 555 0123
Send code
Check your phone
SMSLOCAL · now
Your code is 481 920. It expires in 5 minutes.
SMSWhatsAppVoice
Enter the code
481920
Number verified
Reach users where they are
SMS is the default. Add WhatsApp or voice when SMS is not the best route.
Passcodes go out by SMS.
One flow, many moments
The same passcode flow works for sign-up, login, password reset and confirming a payment.
02Login
481920 is your YourApp login code.
Add a second step to sign-in without asking users to install anything.
03Password reset
Use 481920 to reset your YourApp password.
Check that the owner is asking before a password changes.
04Payment
Confirm your payment of $25.00 with code 481920.
Make sure the account holder approves before money moves.
Choose how your passcode behaves
Length, lifetime and tries are rules in your own app, and NIST guidance is a good starting point. See what each choice means.
Length
Lifetime
Tries allowed
A 6-digit code that works for 5 minutes and allows 3 tries.
Solid against blind guessing
A random guess lands within 3 tries about 1 in 333,333 times.
These rules live in your own app. Pair them with a limit on how often a number can ask for a new code. We deliver the passcode; you decide how it behaves.
Spot where users drop off
Delivery tracking for every passcode shows which step of sign-up loses people. Check numbers first with the Number Lookup API.
Example sign-up funnelIllustrative
- −38 lost
- −116 lost
- −35 lost
Delivery reports show which messages reached a phone and which did not, so a bad route or a mistyped number stands out.
Answers To Your Questions
Verify API — frequently asked questions
SMS is the default. WhatsApp and voice can be added as other ways to reach the user.
Yes. The same flow works for sign-up, login, password reset and confirming a payment.
Yes. SMS to Indian numbers must use approved sender and template registrations, and our team helps you with them.
Get Started
Make verification the easy part
Talk to us about adding passcode verification to your sign-up flow.