| Business | Phone |
| T C Brokers Inc 6003 Bridgehead Rd, Antioch 94509 | (925) 706-9800 |
| Basic Telephone Solutions 2402 Crystal Way, Antioch 94531 | (925) 778-1500 |
| Smartech Communications 4834 Vinewood Way, Antioch 94531 | (925) 779-9700 |
| Telephone Jack 5067 Comanche Way, Antioch 94531 | (925) 753-0393 |