The rules do not say. Illinois’ licensing Act and Part 245 do not say where a home services agency’s office must be, and neither mentions home offices or zoning. What Part 245 does require is to "Provide and maintain an office with a working telephone that is staffed during the agency's business hours." The office must also be adequately equipped, kept so client records stay confidential, and meet local fire safety rules. 245.40(a)(12)
The address you choose matters: "The parent agency address/location appears on the Department-issued license." 245.20 Every client contract gives the agency’s street address too. 245.220(b)
Before you commit to a home office, ask IDPH whether it is acceptable (217-782-7412) and check local zoning and fire rules with your city or county. That is our suggestion for a question the rules leave open.