| 331-200 | Bartlett, IL | Wireless | T-mobile Usa |
| 331-201 | Downers Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-202 | Elmhurst, IL | Wireless | Sprint Spectrum L.p. |
| 331-203 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-205 | Aurora, IL | Wireless | T-mobile Usa |
| 331-206 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-207 | Yorkville, IL | Landline | Level 3 Communications |
| 331-208 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-209 | Elmhurst, IL | Wireless | Level 3 Communications |
| 331-212 | Aurora, IL | Landline | Mci Worldcom Communications |
| 331-213 | Naperville, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-214 | Downers Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-215 | Naperville, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-216 | Oswego, IL | Wireless | New Cingular Wireless PCS |
| 331-218 | Wheaton, IL | Wireless | T-mobile Usa |
| 331-220 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-221 | Elmhurst, IL | Landline | Ameritech Illinois |
| 331-225 | Elmhurst, IL | Wireless | Sprint Spectrum L.p. |
| 331-229 | Naperville, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-234 | Sugar Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-240 | West Chicago, IL | Landline | Peerless Network Of Illinois |
| 331-245 | Bartlett, IL | Wireless | T-mobile Usa |
| 331-248 | Geneva, IL | Landline | Comcast Phone Of Illinois DBA Comco |
| 331-250 | Aurora, IL | Wireless | T-mobile Usa |
| 331-251 | Downers Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-253 | T-mobile Usa, Inc. | Wireless | Lombard |
| 331-254 | Illinois (IL) | Wireless | T-mobile Usa |
| 331-256 | Aurora, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-262 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-281 | Naperville, IL | Landline | Ameritech Illinois |
| 331-301 | Aurora, IL | Landline | Local Access LLC |
| 331-302 | Aurora, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-303 | Elburn, IL | Landline | Cibolo Creek Ventures DBA Routepoint Comm Il |
| 331-304 | T-mobile Usa, Inc. | Wireless | Lombard |
| 331-305 | Naperville, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-307 | T-mobile Usa, Inc. | Wireless | Lombard |
| 331-308 | Bandwidth.com Clec, Llc - Il | Landline | Lombard |
| 331-310 | Bandwidth.com Clec, Llc - Il | Landline | Lombard |
| 331-318 | Lemont, IL | Landline | Local Access LLC |
| 331-321 | T-mobile Usa, Inc. | - | Lombard |
| 331-330 | Oswego, IL | Landline | Cricket Communications |
| 331-332 | Naperville, IL | Wireless | Cricket Communications |
| 331-333 | Naperville, IL | Wireless | Cricket Communications |
| 331-425 | Aurora, IL | Wireless | T-mobile Usa |
| 331-431 | Aurora, IL | Wireless | Bandwidth.com Clec |
| 331-444 | Naperville, IL | Landline | Cellco Partnership DBA Verizon Wireless |
| 331-452 | Aurora, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-454 | Aurora, IL | Wireless | Cricket Communications |
| 331-456 | Roselle, IL | Landline | First Communications LLC |
| 331-457 | Naperville, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-462 | Lombard, IL | Landline | Xo Illinois |
| 331-465 | West Chicago, IL | Wireless | New Cingular Wireless PCS |
| 331-472 | Naperville, IL | Wireless | T-mobile Usa |
| 331-481 | Downers Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-551 | Lombard, IL | Wireless | Cricket Communications |
| 331-575 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-625 | Downers Grove, IL | Wireless | Cellco Partnership DBA Verizon Wireless |
| 331-642 | Elmhurst, IL | Wireless | Bandwidth.com Clec |
| 331-643 | Aurora, IL | Wireless | Sprint Spectrum L.p. |
| 331-645 | Elmhurst, IL | Wireless | Sprint Spectrum L.p. |
| 331-684 | Aurora, IL | Landline | Sigecom |
| 331-701 | Cellco Partnership Dba Verizon Wireless - Il | Wireless | Lombard |
| 331-702 | Naperville, IL | Landline | Mci Worldcom Communications |
| 331-703 | West Chicago, IL | Wireless | T-mobile Usa |
| 331-704 | Bandwidth.com Clec, Llc - Il | Landline | Lombard |
| 331-725 | Oswego, IL | Landline | New Cingular Wireless PCS |
| 331-777 | Downers Grove, IL | Landline | Cellco Partnership DBA Verizon Wireless |
| 331-801 | Illinois (IL) | Landline | Teleport Communications America |
| 331-803 | Lemont, IL | Landline | Peerless Network Of Illinois |
| 331-806 | Comcast Phone Of Illinois, Llc Dba Comco - Il | Landline | Lombard |
| 331-808 | Bandwidth.com Clec, Llc - Il | Landline | Lombard |
| 331-814 | T-mobile Usa, Inc. | Wireless | Lombard |
| 331-825 | Illinois (IL) | | Digital Network Access Communications |
| 331-826 | Elmhurst, IL | Wireless | Sprint Spectrum L.p. |
| 331-888 | Warrenville, IL | Landline | Peerless Network Of Illinois |
| 331-903 | Illinois (IL) | Landline | Sbc Internet Services |
| 331-979 | Comcast Phone Of Illinois, Llc Dba Comco - Il | Landline | Lombard |
| 331-980 | T-mobile Usa, Inc. | Wireless | Lombard |
| 331-998 | Cellco Partnership Dba Verizon Wireless - Il | - | Lombard |
| 331-999 | Oswego, IL | Landline | Bandwidth.com Clec |