Just a quick update, for a neater method to stop the post codes having letters stripped out and which won't get broken if the package gets updated, create a file in /core/components/minishop2/custom/order/ called UKOrderHandler.class.php with this code in it:
<?php
class UKOrderHandler extends msOrderHandler {
public function validate($key, $value) {
if ($key == 'index') {
return substr(preg_replace('/[^a-zA-Z0-9]/iu', '',$value),0,10) ? trim($value) : @$this->order[$key];
}
return parent::validate($key,$value);
}
}
Then change ms2_order_handler_class in the system settings to: UKOrderHandler
This will override the default post code validation without changing the add-on's core code.