Need a simple way to confirm real users before granting access? This flow sends a code by voice call and then confirms the same person by email. It is great for signups, trials, bookings, and any high value form.

A hosted form collects the phone, email, name, and preferred voice. A set node creates a voice code, a small code step adds spaces so text to speech reads each digit clearly, and an HTTP request posts to ClickSend to place the call that speaks the code. The user enters the code on a verify page, and an if check allows the next stage only when the code is correct. After the voice check passes, the flow sends a second code by SMTP email, shows a new verify page, and routes to success or fail based on the match.

Setup is simple. You need a ClickSend account and an SMTP sender. Add both credentials in n8n, set the code values, and test with a real phone and inbox. Teams use this to cut manual checks, stop fake numbers early, and protect onboarding. Expect faster screening, fewer bad records, and clearer audit trails for access decisions.

• Form trigger collects phone, email, name, and voice preference
• Set nodes define the voice code and the email code used for checks
• Code node inserts spaces between digits so text to speech reads them clearly
• HTTP Request calls ClickSend Voice API with Basic Auth to speak the code
• If checks compare user input to stored codes and branch to pass or fail
• SMTP Email node sends a second code only after phone verification passes
• Separate success and fail pages give clear feedback to the user
• Voice selection supports male or female speech from the form

• Reduce manual review from 30 minutes to 3 minutes per user
• Automate up to 90% of verification steps with no manual calls
• Lower invalid contact entries by about 60% by gating email after phone check
• Handle up to 10 times more signups without extra staff
• Connect voice calls and email in one flow for a clear audit trail

1. Import the template into n8n: Create a new workflow in n8n > Click the three dots menu > Select 'Import from File' > Choose the downloaded JSON file.
2. You'll need accounts with ClickSend and SMTP. See the Tools Required section above for links to create accounts with these services.
3. In your ClickSend account, add credit and find your API key in the dashboard. Make sure your phone number format is international with a leading + and country code.
4. In the n8n Credentials manager, create a new HTTP Basic Auth credential for ClickSend. Use your ClickSend username and the API key as the password. Name the credential so your team can find it later.
5. Open the Send Voice node. Select the ClickSend credential. Confirm the URL is https://rest.clicksend.com/v3/voice/send and Content Type is application/json.
6. Open the On form submission node. Confirm fields for To, Voice, Name, and Email. Keep the phone in E.164 format like +15551234567 and set voice options to male or female.
7. Open the Set voice code node and Set email code node. Enter the values you want to verify. Make sure the values used in the verify forms and If checks match these codes.
8. Review the Code for voice node. It adds spaces between digits so the call reads each number clearly. Adjust only if you change the code format.
9. In the n8n Credentials manager, create a new SMTP credential with your mail host, port, username, and password. Enable TLS if your provider requires it. Test with a known inbox.
10. Open the Send Email node. Choose your SMTP credential, set the From address you own, and confirm the To and subject fields use the form data and the email code.
11. Activate the workflow and open the public form link. Submit a test with a real phone. When the call arrives, enter the spoken code on the Verify voice page. If no call, check ClickSend balance, phone format, and credentials.
12. After passing the voice check, watch for the email with the second code. If it does not arrive, review SMTP logs, spam folder, and DNS records like SPF and DKIM. Enter the code to reach the Success page.