Each server to server SOAP call to PayU's API will require a SOAP header with a username and password defined. The SOAP header provides an extra layer of security for the merchant's transaction.
An example of a PayU SOAP header XML is:
<wsse:Security SOAP-ENV:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">
<wsse:UsernameToken wsu:Id="UsernameToken-9" xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
<wsse:Username>PayU provided SOAP username</wsse:Username>
<wsse:Password Type="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-username-token-profile-1.0#PasswordText">PayU provided SOAP password</wsse:Password>
</wsse:UsernameToken>
</wsse:Security>