A phone number is only useful if it's real and belongs to the person who typed it. The surest way to know is to send a code to that number and ask for it back, and in much of the world the place people will actually see that code within seconds is WhatsApp.
This guide shows how a WhatsApp OTP form works, how to set one up in about five minutes without a Meta account, what it costs, and when SMS or email codes are the better choice.
Why WhatsApp codes?
- People see them. In countries where WhatsApp is the main messaging app, such as India, Brazil and Indonesia, a WhatsApp message gets read faster than an SMS among bank alerts and promotions.
- No SMS registration. Business SMS often needs paperwork first. In India, for example, sender IDs and message templates have to be registered on the DLT platform before texts are delivered.
- It proves more than the format. A pattern check stops typos; a code proves the person can receive messages on that number, so made-up and borrowed numbers can't get through.
How a WhatsApp-verified form works
| Step | What happens |
|---|---|
| 1. Enter number | The respondent types their number and taps Send code. |
| 2. Code on WhatsApp | A 6-digit code arrives on WhatsApp from the form's official sender. |
| 3. Type it back | They have 5 minutes and 5 tries. A new code can be requested after 60 seconds, up to 3 times. |
| 4. Verified | The number is marked verified. They have 24 hours to finish and submit the form. |
| 5. Checked on submit | The server accepts the response only if that exact number was verified, so the step can't be skipped. |
Set it up in Tapzy (about 5 minutes)
Step 1: Create a form
Sign up for Tapzy, go to Forms and create a form, or start from a template such as a contact form or lead quiz.
Step 2: Add a Phone field
Add a Phone question where you ask for contact details.
Step 3: Switch on WhatsApp codes
In the field's settings, switch on Verify with a one-time code and choose WhatsApp. There's no account, number or template to connect.
Step 4: Set the countries
Pick a default country and limit Accept numbers from to the countries you serve, so codes only go where you do business.
Step 5: Test it with your own number
Open the form, enter your number, tap Send code and type the code from WhatsApp. A test uses one credit.
Step 6: Publish and use verified responses
Share the form by link, QR code, embed or your bio page. Verified numbers are marked in your responses, and you can send only verified responses to Google Sheets, webhooks, your Meta Pixel and your email alerts.
WhatsApp vs SMS vs email codes
| SMS | |||
|---|---|---|---|
| Proves | Phone number | Phone number | Email address |
| Reaches | People with WhatsApp | Any mobile phone | Anyone with an inbox |
| Setup in Tapzy | None | Your Twilio account | None |
| Cost | One credit per code | Billed by Twilio per text | No per-code cost |
| Best for | Leads and enquiries where WhatsApp is widely used | Audiences that don't use WhatsApp | When you'll follow up by email |
You can verify both on one form: a WhatsApp code on the phone question and an email code, or Google sign-in, on the email question.
What it costs
In Tapzy, every WhatsApp code uses one credit. Every account gets 10 free credits to try it, paid plans include credits each month, and you can buy more at any time. If WhatsApp can't deliver a code, for example because the number isn't on WhatsApp, the credit comes back. Code verification itself is part of Tapzy Pro; the pricing page has the details.
Doing it yourself
Sending WhatsApp codes from your own system is possible, but there's a lot to set up before the first message:
- A Meta business account and a phone number registered on the WhatsApp Business Platform.
- An approved authentication message template.
- Meta's per-message charge for every code sent.
- Code storage, expiry, retry limits and abuse protection on your server, plus the check at submit.
Worth it for an app with millions of sign-ins. For forms, a builder that already does it saves weeks. If you run campaigns on WhatsApp too, MYWA, which powers Tapzy's codes, is a WhatsApp Business API platform for that.
Tips for more completed forms
- Say it up front. “We'll send a code to your WhatsApp” in the question's description stops people wondering why they need their phone.
- Ask for the number once they're invested. Put the phone question after a few easy questions, not first.
- Keep the default country right. Most failed codes are numbers entered without, or with the wrong, country code.
- Watch who stops at the code. Partial responses show what people typed before they left, so you can see whether the code step loses anyone.
- Offer another route on forms where many people don't use WhatsApp: SMS codes, or an email code instead.
Using this for leads? See verified property enquiries and admission enquiries, or the full OTP verification guide for email and SMS too.