A Web browser provides a customized display of phone and fax numbers within a Web page according to user settings. A special phone or fax tag within the Web page file identifies an alphanumeric telephone number within the display (for example, 1-888-IBM-HELP). The telephone number data within the tagged field is converted into a preferred format, as specified at the customization settings page of the Web browser (for example, all numeric 1-888-426-4357). The conversion is preferably displayed upon user indication or activation such as placement of a cursor in proximity to the area occupied by the telephone number within the Web page. A mouse click or keyboard command causes an action within the computer system, as specified within the customization page for the Web browser. For example, by clicking on the telephone number, it is loaded into another software application to connect a telephone call or to send a fax to the telephone number.