I never knew this before today, so I thought I would pass on the information. It is unlawful to take collection actions against a cosigner without sending them a 15 day notice to pay pursuant to the Illinois Consumer Fraud and Deceptive Business Practices Act.
The Act provides that "No person may .... take any collection action regarding a cosigner of an obligation unless prior thereto, such person has notified the cosigner by first class mail that the primary obligor has become delinquent or defaulted on the loan, that the cosigner is responsible for the payment of the obligation and that the cosigner must, within 15 days from the date such notice was sent, either pay the amount due under the obligation or make arrangements for payment of the obligation." 815 ILCS 505/2S.
Any person violating this Section commits an unlawful practice within the meaning of the Act and, in addition, is liable in a civil action for actual damages, plus reasonable attorney's fees.