Switch to O2

With this application you can immediately find out the operator of any Czech phone number you wish to call.

Just follow these steps:

• Enter the phone number
• Select the date; the application will tell you to which network this phone number belonged on that day (up to two months in the past)
• Copy the code you see in the grey field below into the text box
• Information will appear on this page informing you whether or not the number has been transferred to another network.