How to validate SWIFT or BIC Codes using PHP and Regular Expressions

BIC and SWIFT codes have a pretty simple format, and are therefore not that difficult to validate with PHP using regular expressions. Indeed, before we look into the regular expression itself, let us have a look at the build-up of a SWIFT/BIC Code. We will use the Swiss bank UBS' Code as an example: UBSWCHZH80A.

UBSW is the bank code consisting of 4 Alphabetic Symbols.

CH is the country, in this case Switzerland, made up out of 2 Alphabetic Symbols.

ZH is the area code, in this case Z|rich. This part of the code consists of two alphanumeric symbols. If the second symbol is a 1, the participant is passive. If it is a 0 we are dealing with a test-BIC.

80A is the 3 symbol branch code, which also consists of alphanumeric symbols and is optional.

Add all this information up and we end up with the following regular expression:

^([a-zA-Z]){4}([a-zA-Z]){2}([0-9a-zA-Z]){2}([0-9a-zA-Z]{3})?$

And here is an example of a validation code being tested on various real BIC and SWIFT codes, and a few dummy ones:

<?php

function swift_validate($swift)
{

if(!eregi("^([a-zA-Z]){4}([a-zA-Z]){2}([0-9a-zA-Z]){2}([0-9a-zA-Z]{3})?$", $swift))
{

return "<b style='color:#FF0000;'>SWIFT code <i>is not</i> valid.</b>";

}
else
{

return "<b style='color:#0032EA;'>SWIFT code <i>is</i> valid.</b>";

}

}

echo "<b>SWIFT-BIC Natwest Offshore Bank - GB: RBOSGGSX</b><br><br>";

echo 'swift_validate("RBOSGGSX") -> '.swift_validate("RBOSGGSX")."<br><br>";

echo "<b>SWIFT-BIC Raiffeisenbank Kitzb|hel - Austria: RZTIAT22263</b><br><br>";

echo 'swift_validate("RZTIAT22263") -> '.swift_validate("RZTIAT22263")."<br><br>";

echo "<b>SWIFT-BIC Banque et Caisse d'Epargne de l'Etat - Luxemburg: BCEELULL</b><br><br>";

echo 'swift_validate("BCEELULL") -> '.swift_validate("BCEELULL")."<br><br>";

echo "<b>SWIFT-BIC Deutschen Bundesbank - Germany: MARKDEFF</b><br><br>";

echo 'swift_validate("MARKDEFF") -> '.swift_validate("MARKDEFF")."<br><br>";

echo "<b>SWIFT-BIC Volksbank Jever - Germany: GENODEF1JEV</b><br><br>";

echo 'swift_validate("GENODEF1JEV") -> '.swift_validate("GENODEF1JEV")."<br><br>";

echo "<b>SWIFT-BIC UBS AG - Switzerland: UBSWCHZH80A</b><br><br>";

echo 'swift_validate("UBSWCHZH80A") -> '.swift_validate("UBSWCHZH80A")."<br><br>";

echo "<b>SWIFT-BIC Clearstream Banking - S.A., Luxembourg: CEDELULLXXX</b><br><br>";

echo 'swift_validate("CEDELULLXXX") -> '.swift_validate("CEDELULLXXX")."<br><br>";

echo "<b>Invalid Dummy Bank 1: CE1EL2LLFFF</b><br><br>";

echo 'swift_validate("CE1EL2LLFFF") -> '.swift_validate("CE1EL2LLFFF")."<br><br>";

echo "<b>Invalid Dummy Bank 2: E31DCLLFFF</b><br><br>";

echo 'swift_validate("E31DCLLFFF") -> '.swift_validate("E31DCLLFFF")."<br><br>";

?>