Regex to match Australian Business Number (ABN) - regex

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

Answer 2

REF OLD DEAD LINK: http://www.ato.gov.au/businesses/content.asp?doc=/content/13187.htm&pc=001/003/021/002/001&mnu=610&mfp=001/003&st=&cy=1
Confirm an ABN
The following formula can be used to verify the ABN you are allocated or to verify the ABN issued to a business you deal with.
To verify an ABN:
Subtract 1 from the first (left) digit to give a new eleven digit number
Multiply each of the digits in this new number by its weighting factor
Sum the resulting 11 products.
Divide the total by 89, noting the remainder.
If the remainder is zero the number is valid.
Digit Position
1
2
3
4
5
6
7
8
9
10
11
Weight
10
1
3
5
7
9
11
13
15
17
19
Example, to check the validity of ABN 53 004 085 616
5
3
0
0
4
0
8
5
6
1
6
Subtract 1 from first (left) digit to give new number
4
3
0
0
4
0
8
5
6
1
6
Apply weighting factor
10
1
3
5
7
9
11
13
15
17
19
(4x10)+(3x1)+(0x3)+(0x5)+(4x7)+(0x9)+(8x11)+(5x13)+(6x15)+(1x17)+ (6x19)
40+3+0+0+28+0+88+65+90+17+114
445/89 = 5 remainder 0
The remainder is zero so the number is valid.
Here is a C# Validation:
public static bool ValidateABN(string abn)
{
bool isValid = false;
int[] weight = { 10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19 };
int weightedSum = 0;
//ABN must not contain spaces, comma's or hypens
abn = StripNonDigitData(abn);
//ABN must be 11 digits long
if (!string.IsNullOrEmpty(abn) & Regex.IsMatch(abn, "^\\d{11}$"))
{
//Rules: 1,2,3
for (int i = 0; i <= weight.Length - 1; i++)
{
weightedSum += (int.Parse(abn[i].ToString()) - ((i == 0 ? 1 : 0))) * weight[i];
}
//Rules: 4,5
return ((weightedSum % 89) == 0);
}
return isValid;
}
public static string StripNonDigitData(string input)
{
StringBuilder output = new StringBuilder("");
foreach (char c in input)
{
if (char.IsDigit(c))
{
output.Append(c);
}
}
return output.ToString();
}
And a VB.Net Validation:
Public Shared Function ValidateABN(ByVal abn As String) As Boolean
Dim isValid As Boolean = False
Dim weight() As Integer = {10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19}
Dim weightedSum As Integer = 0
'ABN must not contain spaces, comma's or hypens
abn = StripNonDigitData(abn)
'ABN must be 11 digits long
If Not String.IsNullOrEmpty(abn) And Regex.IsMatch(abn, "^\d{11}$") Then
'Rules: 1,2,3
For i As Integer = 0 To weight.Length - 1
weightedSum += (Integer.Parse(abn(i).ToString()) - (IIf(i = 0, 1, 0))) * weight(i)
Next
'Rules: 4,5
Return ((weightedSum Mod 89) = 0)
End If
Return isValid
End Function
Public Shared Function StripNonDigitData(ByVal input As String) As String
Dim output As New StringBuilder("")
For Each c As Char In input
If Char.IsDigit(c) Then
output.Append(c)
End If
Next
Return output.ToString
End Function

Answer 3

// return false if not correct AU vat format
function ABNValidation (val) {
val = val.replace(/[^0-9]/g, '');
let weights = new Array(10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19);
if (val.length === 11) {
let sum = 0;
weights.forEach(function(weight, position) {
let digit = val[position] - (position ? 0 : 1);
sum += weight * digit;
});
return sum % 89 == 0;
}
return false;
}

Answer 4

Another JavaScript version:
/**
* validate ABN
* #param {string} abn
* #return {boolean} is ABN number valid
*
* 0. ABN must be 11 digits long
* 1. Subtract 1 from the first (left) digit to give a new eleven digit number
* 2. Multiply each of the digits in this new number by its weighting factor
* 3. Sum the resulting 11 products
* 4. Divide the total by 89, noting the remainder
* 5. If the remainder is zero the number is valid
*/
var validateABN = function(abn){
var isValid = true;
//remove all spaces
abn = abn.replace(/\s/g, '');
//0. ABN must be 11 digits long
isValid &= abn && /^\d{11}$/.test(abn);
if(isValid){
var weightedSum = 0;
var weight = [10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19];
//Rules: 1,2,3
for (var i = 0; i < weight.length; i++) {
weightedSum += (parseInt(abn[i]) - ((i === 0) ? 1 : 0)) * weight[i];
}
//Rules: 4,5
isValid &= ((weightedSum % 89) === 0);
}
return isValid;
};
//tests
console.log(validateABN('51824753556'));
console.log(validateABN('51 824 753 556'));
console.log(validateABN('51824744556'));

Answer 5

Have you read up on regexes? This is as straightforward as it gets.
^[0-9 ]+$

Answer 6

For those using AngularJS, I have written a directive to do ABN validation:
var app = angular.module("demoapp", ["input-abn-directive"]);
and
<input type="abn" name="inputAbn" ng-model="modelAbn">
https://github.com/jasadams/input-abn-directive

Answer 7

TESTED ABN Javascript implementation
These are WORKING ABNs:
33 051 775 556 should work
14 069 979 460 should work
24 302 976 253 should work
These are INVALID ABNs:
65 065 987 968 should fail
12 345 678 965 should fail
function checkABN(value) {
let weights = new Array(10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19);
let abn = value.replace(/\D/g, ''); // strip non numeric chars
if (abn.length != 11) {
return false;
}
let abnFirstDigit = parseInt(abn.charAt(0)) - 1; //subtract 1 from first digit
abn = abnFirstDigit + abn.substring(1); // replace first digit with the substracted value
let total = 0;
for (let i = 0; i < 11; i++)
total += weights[i] * abn.charAt(i);
if (total == 0 || total % 89 != 0) {
return false;
} else {
return true;
}
}
The one from http://www.mathgen.ch/codes/abn.html has issues,
it won't allow 14 069 979 460 (which should be valid)

Answer 8

JavaScript version:
function checkABN(str) {
if (!str || str.length !== 11) {
return false;
}
var weights = [10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19],
checksum = str.split('').map(Number).reduce(
function(total, digit, index) {
if (!index) {
digit--;
}
return total + (digit * weights[index]);
},
0
);
if (!checksum || checksum % 89 !== 0) {
return false;
}
return true;
}

Answer 9

Answer to the Question
A lot of answers will include the regex [0-9]{11} or similar, which is sufficient for most situations, but none of the answers take into account the fact that ABNs cannot start with a zero.
The simplest regex available for determining an ABN, that takes into account the correct number of digits, any number of spaces and the non-zero leading digit, is: ^\s*[1-9](\s*\d){10}\s*$.
Standard Format
The standard number format is the 2,3,3,3 digit grouping pattern, as the first two digits form the check digits and the other 9 is the actual identifier.
The regex for specifically checking this format with or without spaces is ^[1-9]\d(\s?\d{3}){3}$.
This format can be easily mimicked using the PHP number_format function.
number_format( '12123123123', 0, '', ' ' ) === '12 123 123 123';
Actual Validation
Any of the other answers relating to actual validation should be mostly valid, but not 100% unless there is an additional check to ensure the number does not start with a zero. Expanding upon the current top rated answer, one additional check just needs to be made.
if ( strlen( $abn ) === 11 && $abn[0] > 0 ) { // or $abn > 9999999999
// ...
}

Answer 10

SQL Server solution - in a single case statement
As described in other answers, a single regular expression is unlikely to be able to validate an ABN. The case statement below can be used in Microsoft SQL Server to validate an ABN. You might like to create a persisted computed column on your table that contains the ABN field. Per comments below, if you return integers instead of text descriptions, then you can use such a field for relatively straightforward comparisons:
1 = valid
0 = invalid (wrong length)
-1 = invalid (fails the pattern check)
allowing you to use expressions like:
where abnValid = 1 -- match all valid records
where abnValid < 1 -- match all invalid records
The logic below for validating ABNs is based on Jeremy Thompson's answer here. The statement below is verbose and inefficient - so that it fits a single case statement so that you can use it with a persisted computed column - meaning the performance hit will be on update, not on select. It assumes your abnColumn is character based - so add an explicit cast if you're using a numeric type. It ignores space characters in your source data and assumes the first number of an ABN will not be zero.
case
when len(ltrim(rtrim(replace(abnColumn,' ','')))) <> 11 then 'Wrong length' -- or perhaps 0
when
(
((try_cast(left(ltrim(rtrim(replace(abnColumn,' ',''))),1) as int)-1)*10) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),10),1) as int)*1) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),9),1) as int)*3) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),8),1) as int)*5) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),7),1) as int)*7) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),6),1) as int)*9) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),5),1) as int)*11) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),4),1) as int)*13) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),3),1) as int)*15) +
(try_cast(left(right(ltrim(rtrim(replace(abnColumn,' ',''))),2),1) as int)*17) +
(try_cast(right(ltrim(rtrim(replace(abnColumn,' ',''))),1) as int)*19)
) %89 <> 0 then 'Check pattern fail' -- or perhaps -1
else 'Valid' -- or perhaps 1
end as abnValidationCheck -- or perhaps abnValid

Answer 11

For those TypeScript with reactive forms and angular2+ out there out there:
this.abnForm = new FormGroup({
abn: new FormControl('', [
this.abnValidator(),
Validators.pattern('^(\d *?){11}$')])
});
abnValidator(): ValidatorFn {
return (control: AbstractControl): ValidationErrors | null => {
const weights = [10,1,3,5,7,9,11,13,15,17,19];
const cleanedABN = control.value.replace(/\D/g, '');
let valid = false;
if (cleanedABN.length === 11) {
let sum = 0;
weights.forEach((weight, ind) => {
const digit = parseInt(cleanedABN[ind], 10) - (ind === 0 ? 1 : 0);
sum += weight * digit;
});
valid = sum % 89 === 0;
} else {
valid = false;
}
return valid ? null : { invalid: true };
};
}