In this article, we will explain to you how to PHP registration with email verification using OTP. so we will give you a simple example of how to send otp email using php(email otp verification).
Sometimes when users register at a time we need to verify to send OTP in the mail. so we will see an example of how this can it possible in PHP.
CREATE TABLE `user` (
`id` int(11) NOT NULL,
`first_name` varchar(255) NOT NULL,
`last_name` varchar(255) NOT NULL,
`email` varchar(255) NOT NULL,
`password` varchar(255) NOT NULL,
`status` enum('0','1') NOT NULL,
`otp` int(11) NOT NULL,
`created_at` datetime DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
--
-- Indexes for dumped tables
--
--
-- Indexes for table `user`
--
ALTER TABLE `user`
ADD PRIMARY KEY (`id`);
--
-- AUTO_INCREMENT for dumped tables
--
--
-- AUTO_INCREMENT for table `user`
--
ALTER TABLE `user`
MODIFY `id` int(11) NOT NULL AUTO_INCREMENT;
COMMIT;
Create a new connection.php file. The code below is to provide how to connect with the database.
The following code is used to connect MySQL from PHP. It requires hostname, database username, database password, and database name.
connection.php
<?php $hostname="localhost"; $username="root"; $password="test"; $database="testdb"; $conn = mysqli_connect($hostname,$username,$password,$database); ?>
Create a new PHP file register.php in this file in add the below code. in this example, we will create the user registration form using PHP. After the submit the register button then we will check all fields are mandatory or not. if all fields are not empty then we will store the data in the database and send OTP email. we send mail using php in the below example.

<?php
if(isset($_POST['btnRegister']))
{
include('connection.php');
$email = $_POST['email'];
$sql=mysqli_query($conn,"SELECT * FROM user where email='$email'");
if(mysqli_num_rows($sql)>0)
{
$msg="Email Id Already Exists";
header ("Location: register.php?error=".$msg);
exit;
}
else
{
$first_name = $_POST['firstname'];
$last_name = $_POST['lastname'];
$password = md5($_POST['password']);
$otp = rand(100000, 999999);
$date = date("Y-m-d H:i:s");
if(!empty($first_name) && !empty($last_name) && !empty($email) && !empty($password)){
$insert="insert into user (first_name,last_name,email,password,status,otp,created_at) values('$first_name','$last_name','$email','$password',0,$otp,'$date')";
mysqli_query($conn,$insert);
require 'class/class.phpmailer.php';
$mail = new PHPMailer;
$mail->IsSMTP();
$mail->Host = 'ssl://smtp.gmail.com';
$mail->Port = '465';
$mail->SMTPAuth = true;
$mail->Username = 'xxxxxxxxxxxx';
$mail->Password = 'xxxxxxxxxxx';
$mail->SMTPSecure = '';
$mail->From = 'Enter Form Email';
$mail->FromName = 'Enter From Name';
$mail->AddAddress($row['email']);
$mail->IsHTML(true);
$mail->Subject = 'User Registration with Email Verification using OTP';
$message_body = '<p>For verify your email address, enter this verification code when prompted:: <b>'.$otp.'</b>.</p>
<p>Sincerely,</p>';
$mail->Body = $message_body;
if($mail->Send())
{
$code = base64_encode($email);
header('location:verify.php?code='.$code);
exit;
}
}
else{
$msg="All fields are mandatory";
header ("Location: register.php?error=".$msg);
exit;
}
}
}
?>
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<title>PHP Registration with Email Verification using OTP</title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="register.php">Register</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</nav>
<div class="container">
<div class="row">
<div class="col-12 col-sm-8 offset-sm-2 col-md-6 offset-md-3 mt-5 pt-3 pb-3 bg-white from-wrapper">
<div class="container">
<h3>Register</h3>
<hr>
<form class="" method="post">
<div class="row">
<div class="col-12 col-sm-6">
<div class="form-group">
<label for="firstname">First Name</label>
<input type="text" class="form-control" name="firstname" id="firstname" value="">
</div>
</div>
<div class="col-12 col-sm-6">
<div class="form-group">
<label for="lastname">Last Name</label>
<input type="text" class="form-control" name="lastname" id="lastname" value="">
</div>
</div>
<div class="col-12">
<div class="form-group">
<label for="email">Email address</label>
<input type="text" class="form-control" name="email" id="email" value="">
</div>
</div>
<div class="col-12 col-sm-6">
<div class="form-group">
<label for="password">Password</label>
<input type="password" class="form-control" name="password" id="password" value="">
</div>
</div>
<div class="col-12 col-sm-6">
<div class="form-group">
<label for="password_confirm">Confirm Password</label>
<input type="password" class="form-control" name="password_confirm" id="password_confirm" value="">
</div>
</div>
<?php if (isset($_REQUEST['error'])): ?>
<div class="col-12">
<div class="alert alert-danger" role="alert">
<?php echo $_REQUEST['error']; ?>
</div>
</div>
<?php endif; ?>
</div>
<div class="row">
<div class="col-12 col-sm-4">
<button type="submit" name="btnRegister" class="btn btn-primary">Register</button>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>
verify.php

<?php
if(isset($_POST['btnVerify']))
{
include('connection.php');
$code = $_REQUEST['code'];
if(!empty($code) && $_POST['otp'] != ""){
$sql=mysqli_query($conn,"SELECT * FROM user where email='".base64_decode($code)."' and status=0");
$row = mysqli_fetch_array($sql);
if(is_array($row))
{
if($_POST['otp'] == $row['otp']){
$msg="User Successfully verified";
header ("Location: verify.php?success=".$msg);
exit;
}
else
{
$msg="Invalid OTP Code";
header ("Location: verify.php?code=".$code."&error=".$msg);
exit;
}
}
else
{
$msg="Invalid OTP Code";
header ("Location: verify.php?code=".$code."&error=".$msg);
exit;
}
}
else{
$msg="All fields are mandatory";
header ("Location: verify.php?code=".$code."&error=".$msg);
exit;
}
}
?>
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<title></title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="verify.php">Verify</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</nav>
<div class="container">
<div class="row">
<div class="col-12 col-sm-8 offset-sm-2 col-md-6 offset-md-3 mt-5 pt-3 pb-3 bg-white from-wrapper">
<div class="container">
<h3>User Verification using OTP</h3>
<hr>
<?php if (isset($_REQUEST['success'])): ?>
<div class="alert alert-success" role="alert">
<?php echo $_REQUEST['success']; ?>
</div>
<?php endif; ?>
<form class="" method="post">
<div class="form-group">
<label for="otp">Enter OTP</label>
<input type="text" class="form-control" name="otp" id="otp" value="">
</div>
<?php if (isset($_REQUEST['error'])): ?>
<div class="col-12">
<div class="alert alert-danger" role="alert">
<?php echo $_REQUEST['error']; ?>
</div>
</div>
<?php endif; ?>
<div class="row">
<div class="col-12 col-sm-4">
<button type="submit" name="btnVerify" class="btn btn-primary">Verify</button>
</div>
<div class="col-12 col-sm-8 text-right">
<a href="resend.php">Resend</a>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>
resend.php

<?php
if(isset($_POST['btnResend']))
{
include('connection.php');
$email = $_REQUEST['email'];
if(!empty($email)){
$sql=mysqli_query($conn,"SELECT * FROM user where email='$email' and status=0");
$row = mysqli_fetch_array($sql);
if(is_array($row))
{
$otp = rand(100000, 999999);
$update_query = "UPDATE user SET otp = '".$otp."' WHERE id = '".$row['id']."'";
mysqli_query($conn,$insert);
require 'class/class.phpmailer.php';
$mail = new PHPMailer;
$mail->IsSMTP();
$mail->Host = 'ssl://smtp.gmail.com';
$mail->Port = '465';
$mail->SMTPAuth = true;
$mail->Username = 'xxxxxxxxxxxx';
$mail->Password = 'xxxxxxxxxxx';
$mail->SMTPSecure = '';
$mail->From = 'Enter Form Email';
$mail->FromName = 'Enter From Name';
$mail->AddAddress($row['email']);
$mail->IsHTML(true);
$mail->Subject = 'Resend Email Verification OTP For Registration';
$message_body = '
<p>For verify your email address, enter this verification code when prompted:: <b>'.$otp.'</b>.</p>
<p>Sincerely,</p>
';
$mail->Body = $message_body;
if($mail->Send())
{
$code = base64_encode($row['email']);
header('location:verify.php?code='.$code);
exit;
}
}
else
{
$msg="Email Address already verified";
header ("Location: resend.php?error=".$msg);
exit;
}
}
else{
$msg="All fields are mandatory";
header ("Location: verify.php?code=".$code."&error=".$msg);
exit;
}
}
?>
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<meta charset="utf-8">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">
<title>Resend Email Verification OTP using PHP</title>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-dark">
<div class="container">
<a class="navbar-brand" href="resend.php">Resend</a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
</div>
</nav>
<div class="container">
<div class="row">
<div class="col-12 col-sm-8 offset-sm-2 col-md-6 offset-md-3 mt-5 pt-3 pb-3 bg-white from-wrapper">
<div class="container">
<h3>Resend Email Verification OTP</h3>
<hr>
<?php if (isset($_REQUEST['success'])): ?>
<div class="alert alert-success" role="alert">
<?php echo $_REQUEST['success']; ?>
</div>
<?php endif; ?>
<form class="" method="post">
<div class="col-12">
<div class="form-group">
<label for="email">Email address</label>
<input type="text" class="form-control" name="email" id="email" value="">
</div>
</div>
<?php if (isset($_REQUEST['error'])): ?>
<div class="col-12">
<div class="alert alert-danger" role="alert">
<?php echo $_REQUEST['error']; ?>
</div>
</div>
<?php endif; ?>
<div class="row">
<div class="col-12 col-sm-4">
<button type="submit" name="btnResend" class="btn btn-primary">Resend</button>
</div>
</div>
</form>
</div>
</div>
</div>
</div>
<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js" integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q" crossorigin="anonymous"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js" integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl" crossorigin="anonymous"></script>
</body>
</html>