You will be automatically registered to PayU myAccount service when you first place an order in the PayU network. You can retrieve your login credentials using the ‚‚Retrieve password’’ function here: https://secure.http://www.payu.ro/myaccount/
No. Prefilled data are only available for future orders made from the same PC.
If you use several PCs you need to prefill your data in your myAccount, on each computer. However, you should activate this option only on your personal computer. You also shouldn't use the remember password option in the browser unless you are the only one who uses that computer.