PHP phone number validation – revisited

Several months ago, when I was first getting familiar with regular expression, I made a post talking about PHP form validation for phone numbers and email addresses.

A couple of days ago, I revisited that post and realized how inefficient my function actually was. The entire point of regex is to recognize multiple patterns within 1 statement. Here is my revised regular expression.

/^(\d[\s-]?)?[\(\[\s-]{0,2}?\d{3}[\)\]\s-]{0,2}?\d{3}[\s-]?\d{4}$/i

This single function detects for all the patterns in the original post and more.

Example

$phone_numbers = array( 
    '555-555-5555',
    '5555425555',
    '555 555 5555',
    '1(519) 555-4444',
    '1 (519) 555-4422',
    '1-555-555-5555',
    '1-(555)-555-25555',
);
$regex = "/^(\d[\s-]?)?[\(\[\s-]{0,2}?\d{3}[\)\]\s-]{0,2}?\d{3}[\s-]?\d{4}$/i";
foreach( $phone_numbers as $number ) {
    echo $number . ': ' . ( preg_match( $regex, $number ) ? 'valid' : 'invalid' ) . '<br/>';
}

Output

555-555-5555: valid
5555425555: valid
555 555 5555: valid
1(519) 555-4444: valid
1 (519) 555-4422: valid
1-555-555-5555: valid
1-(555)-555-5555: valid
1-(555)-555-25555: invalid

5 thoughts on “PHP phone number validation – revisited”

  1. Complex regular expressions are often hard to read and therefor can be a pain to write and debug.

    It is always useful to seek for proven regex before even thinking about writing one.

    Thank you

  2. Does it work for non-USA numbers though?

    +55-32-1233-4567

    would that read as “valid” or “invalid” with your code?

    1. Hi Steven,

      This particular regex wouldn’t work for non-North American Numbers. This regex expression would work for the number you have above.

      ^\+?\d{2}[\s-]?\d{2}[\s-]?\d{4}[\s-]?\d{4}$

      Note, this would ONLY work for the format you provided, as well as the following alternatives:

      +55-32-1233-4567
      55-32-1233-4567
      55 32 1233 4567
      553212334567

      The + is optional, the dashes can be spaces or nothing. Hope this helps!

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