| Business | Phone |
| Water Softener Plant Kelsan Hts, Illiopolis 62539 | (217) 486-3131 |
| Illiopolis Township Office 407 5th St, Illiopolis 62539 | (217) 486-3441 |
| Illiopolis Twp Sewer Plant Illiopolis 62539 | (217) 486-6241 |
| Illiopolis Twp Shed 250 W Maple Ln, Illiopolis 62539 | (217) 486-6032 |
| Illiopolis Village Hall 302 5th St, Illiopolis 62539 | (217) 486-2511 |
| Illiopolis Village Shed 804 Louise St, Illiopolis 62539 | (217) 486-6210 |