Please be AWARE that there is an issue with Excel in the way that it converts data from an Excel Spreadsheet to a .CSV (Comma Delimited) file.
Unfortunately this is an Excel issue, you will notice that your contact's numbers will be missing the '0' from the start of the number and the '0' will be replaced by '44' with the remaining part of the number displayed, as shown in the screenshot below:
If you are importing contact numbers to use for VoIP calls or for SMS messaging this will not affect your ability to make outbound calls to the number as using our Click2Call system the phone call will still be made successfully to the number even though the '0' is missing.
The same applies for SMS messaging, the SMS will still be sent to your contact even though the '0' at the front of the mobile number is missing.