Ill. Admin. Code tit. 86 § 280.130
An ordinance or resolution imposing or effecting a change in the rate of a Home Rule Municipal Service Occupation Tax shall either: be adopted and a certified copy filed with the Department on or before the first day of April, whereupon the Department shall proceed to administer and enforce the ordinance or resolution as of the first day of July next following such adoption and filing; or be adopted and a certified copy filed with the Department on or before the first day of October, whereupon the Department shall proceed to administer and enforce the ordinance or resolution as of the first day of January next following such adoption and filing. For this purpose, the date of the sale of service is deemed to be the date of the delivery, to the user, of the tangible personal property which the serviceman retransfers as an incident to service.
Ill. Admin. Code tit. 86, § 280.130
Amended at 24 Ill. Reg. 8114, effective May 26, 2001