I called the ISP to change the address on my FOID back on May 2 and still haven't gotten the updated FOID card. After a little research it looks like their policy is to just note the address change and not actually send a new card, which I find odd given that they charge you $5+$1 processing fee. I took a look at the statute that sets out the fees for these things and I don't think they're doing it correctly. I think the correct reading of the statute is $5 should get you a new card for name or address change. I could also see a reading of the statute that says you simply have to notify them about an address change with no charge and $5 gets you a new card for a name change. I cannot see a reading of the statute that allows for a $5 charge for an address change that doesn't get you a new card.
(430 ILCS 65/13.2) (from Ch. 38, par. 83-13.2)
Sec. 13.2. The Department of State Police shall, 60 days prior to the expiration of a Firearm Owner's Identification Card, forward by first class mail to each person whose card is to expire a notification of the expiration of the card and an application which may be used to apply for renewal of the card. It is the obligation of the holder of a Firearm Owner's Identification Card to notify the Department of State Police of any address change since the issuance of the Firearm Owner's Identification Card. Whenever any person moves from the residence address named on his or her card, the person shall within 21 calendar days thereafter notify in a form and manner prescribed by the Department of his or her old and new residence addresses and the card number held by him or her. Any person whose legal name has changed from the name on the card that he or she has been previously issued must apply for a corrected card within 30 calendar days after the change. The cost for a corrected card shall be $5 which shall be deposited into the State Police Firearm Services Fund.