Texas Collin County: All Zip Codes. Dallas County Zip Codes:76006 75040 75041 75043 75044 75048 75080 75081 75082 75088 75089 75234 75240 75244 75248 75252 Denton County Zip Codes: 75007 75009 75010 75033 75034 75056 75057 75067 75068 75077 75078