class MSSoapClient extends SoapClient {
    private $namespace;
    function __doRequest($request, $location, $action, $version) {
        

        $request = preg_replace('/<ns1:(\w+)/', '<$1 xmlns="'.$this->namespace.'"', $request, 1);
        $request = preg_replace('/<ns1:(\w+)/', '<$1', $request);
        $request = str_replace(array('/ns1:', 'xmlns:ns1="'.$this->namespace.'"'), array('/', ''), $request);
        
        // parent call
        return parent::__doRequest($request, $location, $action, $version);
    }
    function setNamespace($sNamespace)
    {
        $this->namespace=$sNamespace;
    }
    
}  

To make a new customer - I'm only you can extend the function to add other details to the record.

function newKashflowCustomer($soapClient,$idAccount,$name,$address,$town,$postcode,$country,$email)
{
    //returns customer id if ok else 0
    
    $today = date("Y-m-d",mktime());
    
    $customerArray = array(
        "CustomerID"=>"",
        "Code"=>"",
        "Name"=>"$name",
        "Contact"=>"",
        "Telephone"=>"",
        "Mobile"=>"",
        "Fax"=>"",
        "Email"=>"$email",
        "Address1"=>"$address",
        "Address2"=>"",
        "Address3"=>"$town",
        "Address4"=>"$country",
        "Postcode"=>"$postcode",
        "Website"=>"",
        "EC"=>"0",
        "Notes"=>"",
        "Source"=>"",
        "Discount"=>"0",
        "ShowDiscount"=>"0",
        "PaymentTerms"=>"0",
        "ExtraText1"=>"1",
        "ExtraText2"=>"1",
        "CheckBox1"=>"1",
        "CheckBox2"=>"1",
        "Created"=>"$today",
        "Updated"=>"$today");
    
    $args = array ("UserName"=>"your username here", "Password"=>"your password here","custr"=>$customerArray);
    $oResponse = $soapClient->InsertCustomer($args);
    //handle any errors
    if($oResponse->Status != "OK")
    {
        echo $oResponse->StatusDetail;
        $return = 0;

    }
    else
    {
        $id = $oResponse->InsertCustomerResult;
        
        $return = $id;
        
    }
    return $return;
}