Verify phone numbers. Without sending a code.
Your visitor sends a short code from their own phone, via WhatsApp or, where you allow it, by SMS. The number the message comes from is the verified number. Nobody types a number, and nothing goes out from your side.
- No phone number field
- Number from the provider, not from a form
- Pay per verified number
Sign-ups by message. No form, no code.
Sendity is a sign-up widget for your website. Instead of filling in a form, your visitors send one short message via WhatsApp or email. Sendity checks who it came from and hands your site the name and the confirmed phone number or email address.
See how Sendity works →-
One message instead of a form Visitors tap send in WhatsApp or their email app. Nothing to type, no confirmation email to click.
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Confirmed by the message itself The contact comes from the sender of the message, so typos and made-up addresses never reach your list.
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Pay per confirmed contact Start with 1,000 free credits, no credit card. After that, prepaid packages with no subscription.
A verified number is only as good as the evidence behind it. Sendity takes that evidence from the message itself, not from what someone typed.
Why outbound codes are the weak spot
With a classic one-time code you send an SMS to whatever number someone entered. A wrong digit sends it to a stranger, delivery can take minutes, and every message is billed whether it arrives or not. Bots exploit exactly this: they enter premium-rate numbers and let your form trigger expensive SMS, a fraud known as SMS pumping.
The visitor sends, the provider confirms
Sendity shows each visitor a short-lived code for this visit. They send it from their phone. For WhatsApp, the official Meta Cloud API reports which number the message came from, and Sendity binds that number to the live code. Your site receives the verified number as a signed result.
Checks before a number counts
Sendity verifies the signature of every Meta webhook, accepts only messages to the configured business number, rejects stale and duplicate deliveries and requires a matching, unexpired code. Your backend then validates the signed result before it creates an account, accepts an entry or grants access.
What a verified number proves
It shows that the sender controlled the WhatsApp account behind that number at the time of verification. It does not prove a legal identity or that they will keep the number. If WhatsApp only provides a user ID without a number, the verification stays incomplete until the visitor shares their number.
SMS for visitors without WhatsApp
Per campaign you can allow SMS as a fallback. The visitor chooses it deliberately and sends the same code by SMS from their own phone. It reaches people without WhatsApp, but the sender evidence of an SMS is weaker, so decide per campaign whether it fits.
Show, send, verified.
Three steps, and your visitor never types their number.
Your page shows a code
As a QR code on a computer, as a button on a phone. Each visit gets its own short-lived code.
The visitor sends it
WhatsApp opens with the message already written. One tap on send, or SMS if you allow it.
Your backend gets the number
As a signed result with the verified number and the WhatsApp profile name. Your page moves on immediately.
Outbound OTP or a code from the visitor?
The direction of the message changes what you pay for and what can go wrong.
| Aspect | Outbound SMS or WhatsApp OTP | With Sendity |
|---|---|---|
| Who sends | You, to a number someone typed in | The visitor, from their own phone |
| Where the number comes from | A form field | The messaging provider |
| Failed deliveries | Billed even if the code never arrives | Nothing is sent, so nothing fails |
| SMS pumping | Bots can trigger paid SMS to premium numbers | No outbound code a bot could trigger |
| Verification fee | Managed OTP services charge per verification on top of delivery | 4 prepaid credits per verified number |
Real numbers, predictable costs.
Fewer steps for your visitors and less exposure for your budget.
No typos, no strangers
The number comes from the message, so a wrong digit cannot send a code to someone else.
Nothing to pump
On the WhatsApp path you send no code at all, so bots cannot run up an SMS bill through your form.
Your app decides
You get a signed result and decide what a verified number unlocks: an account, an entry or a seat.
What 250 verified numbers cost
Your first 1,000 credits are free, no credit card needed. Each verified phone number uses 4 credits, and packages from €100 include bonus credits. No charge for codes that never arrive, because Sendity sends none. Package prices exclude VAT.
Live on your page in minutes.
Sendity runs as a compact widget on your page. Pick the path that fits your website.
Questions about phone verification.
How is this different from WhatsApp verification?
WhatsApp is the main channel for phone numbers. This page covers phone verification as a whole: the checks behind it, the optional SMS fallback and how the costs compare with outbound codes.
Can visitors without WhatsApp verify their number?
If you allow SMS fallback for the campaign, yes. They choose it deliberately and send the same code by SMS. The sender evidence is weaker than with WhatsApp.
Does a verified number prove who someone is?
No. It shows control of the WhatsApp account behind the number at that moment, not a legal identity.
What does a verified number cost?
4 credits. You start with 1,000 free credits, and only successful verifications are billed.
Verify your next number without sending a code.
Try the live demo on your phone. It takes ten seconds.