Yes; you can setup a Notification (POST) to send data back to your system at the end of the transaction. More information can be found in the Rule Manager documentation.
There is no specific URL to your payment page as such; it exists as part of the POST to our main URL, which is: https://payments.securetrading.net/process/payments/choice
Provided you keep them separate on your server (and separate the versions of Java if relevant), then yes; this is possible.
The most likely cause of this error is when a carriage return does not exist at the very end of the XML file, or the XML file is truncated before the end.
This is usually caused by your STAPI client not running when you attempt to send the request through.
The most likely cause of this would be incorrect credentials in your Web Services header, or you are using a username that is not setup as the Web Services role.
It is likely that the Site Reference quoted in your XML is not linked to your Web Services username, or the value you are passing for ALIAS in the XML is invalid (it must be the Web Services username).
Yes, the Site Admin (main user) can create other users and provide them with their own access levels. We strongly advise that you use individual logins as you may require this for PCI accreditation, and this will also log which username has performed an action.
Send an email to [email protected] from an authorised contact, provide your MyST username and request a password reset.