Regex to match Australian Business Number (ABN)

Question

I need a regex to match a value in which each character can be a digit from 0 to 9 or a space. The value must contain exactly 11 digits.

For example, it should match values in the format '012 345 678 90' or '01234567890'.

Can anyone please help me on this?

Answer 1

For the sake of other Aussie developers out there who may find this in the future:

^(\d *?){11}$

Matches 11 digits with zero or more spaces after each digit.

Edit:

As @ElliottFrisch mentioned, ABNs also have a mathematical formula for proper validation. It would be very difficult (or impossible) to use regex to properly validate an ABN - although the above regex would at least match 11 digit numbers with spacing. If you're after actual validation, perhaps regex isn't the tool for you in this case.

Further reading:

https://abr.business.gov.au/Help/AbnFormat

Here's a PHP implementation:

http://www.clearwater.com.au/code

Code copied from the above page in case it becomes unavailable someday:

//   ValidateABN
//     Checks ABN for validity using the published 
//     ABN checksum algorithm.
//
//     Returns: true if the ABN is valid, false otherwise.
//      Source: http://www.clearwater.com.au/code
//      Author: Guy Carpenter
//     License: The author claims no rights to this code.  
//              Use it as you wish.

function ValidateABN($abn)
{
    $weights = array(10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19);

    // strip anything other than digits
    $abn = preg_replace("/[^\d]/","",$abn);

    // check length is 11 digits
    if (strlen($abn)==11) {
        // apply ato check method 
        $sum = 0;
        foreach ($weights as $position=>$weight) {
            $digit = $abn[$position] - ($position ? 0 : 1);
            $sum += $weight * $digit;
        }
        return ($sum % 89)==0;
    } 
    return false;
}

And a javascript one which I found here:

http://www.mathgen.ch/codes/abn.html