Yes if you are using a Desk Phone that plugs straight into an ethernet port either on a router or via a switch.  

However please note that your broadband will need to be of sufficient quality and bandwidth in order to support having multiple VoIP lines and the use of the web.  


Some businesses use a two separate broadband lines one dedicated for VoIP, the other for the internet so you may need to speak with your current broadband provider about this.