We spoke to an attorney at the IDPFR, and their guidance was to take extreme caution in serving as a guarantor of a customer’s credit card. While the agency understands that the Illinois Banking Act does authorize Illinois-chartered banks to “do any act . . . that is at the time authorized or permitted to national banks” (205 ILCS 5/5(11)), it is not clear that national banks are authorized to serve as guarantors of lines of credit for their customers. The question hinges on the OCC regulation that you identified, which permits national banks to “guarantee obligations of a customer . . . that are financial in character, provided the amount of the bank’s financial obligation is reasonably ascertainable and otherwise consistent with applicable law,” that power should be available to Illinois-chartered banks. 12 CFR 7.1017. Because that OCC regulation has not issued any official interpretations that would address the situation you described, the IDFPR was not able to say whether a state-chartered bank could serve as a guarantor for a customer’s credit card debt.

Also, while the Banking Act explicitly authorizes Illinois banks to issue letters of credit, and at least one 7^th Circuit case interpreted that provision to allow a bank to issue a guarantee that fits the UCC definition of “letter of credit,” it is not clear that the Banking Act would authorize a credit card guarantee in this situation. Bank of North Carolina, NA v. Rock Island Bank, 570 F. 2d 202, 206­–207 (7th Cir. 1978); 205 ILCS 5/5(13).