You and the buyer must have a FOID card, buyer must present FOID card before handling firearms. Buyer has to wait 72 hours to take possession from the point a sale is agreed upon. You need to keep a record of the sale for 10 years, including who the firearm is transfered to, date of transfer, description of the firearm (make, model, see. no.), and as of last year you need to verify they buyer's FOID through the Illinois State Police website (second link below). Record the FOID verification number on the record of sale as well.