SYS(8007) - Make a phone call

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Initiates a phone call on mobile devices with phone support.


SYS( 8007, cNumber )



Specifies the phone number to dial. The number must be in a format that the phone understands and should only consist of digits. International numbers can start with a "+" sign followed by digits only.

Return value

Returns a string indicating whether the call has been successfully initiated. The return value is "1" on successful calls and "0" when there was some problem. There's no additional information available about what the problem was.


When a call is initiated while another call is in progress, the first call is put on hold until the second call finishes.


During dialing the phone might display a progress dialog and additional error messages. These dialogs are not customizable.


When testing your application on an actual phone be aware that placing a phone call actually costs money. The actual amount depends on the number dialled and your calling plan. To test applications with phone functionality it's recommended to use the device emulator for the initial development.


SYS(8007) is only available with the Microsoft Compact Framework. The function is ignored on any platform other than Windows Mobile. If the device does not have phone support, SYS(8007) raises a feature not available error message or returns an error status.

Runtime libraries

The following DLLs must be available in either the application directory, the system directory or the global assembly cache in order to call this function: