Regex to validate KRA PIN

kra_pin_regex.php

<?php     
$kra_regex = "/^[A]{1}[0-9]{9}[a-zA-Z]{1}$/";
$kra_pin = "A001234567J";

if(preg_match($kra_regex, $kra_pin)){
  echo "Success! Valid KRA PIN";
}
else{
  echo "Error! Invalid KRA PIN";
}

kra_pin_validation_helper.php

<?php

function isPinValid($pin)
{
  return preg_match("/^[A]{1}[0-9]{9}[a-zA-Z]{1}$/", $pin);
}

$is_valid = isPinValid("A001234567J");