you can generate a 10-digit unique number that never duplicates using various techniques. One common approach is to use a combination of random numbers and a checksum digit. Here's an example implementation in PHP:

generate a 10-digit unique number that never duplicates.php

function generate_unique_number() {
    $number = mt_rand(1000000000, 9999999999); // Generate a random 10-digit number
    $sum = 0;
    for ($i = 2; $i <= 11; $i++) { // Calculate the checksum digit
        $digit = substr($number, 11 - $i, 1);
        $sum += $digit * $i;
    }
    $checksum = ($sum % 11) == 10 ? '0' : ($sum % 11); // If the checksum is 10, replace it with 0
    return substr($number, 0, 9) . $checksum; // Return the number with the checksum digit appended
}