Similar to the Illinois Notice to Quit, a Notice to Pay Rent informs the tenant that they are not complying with the lease terms (they owe rent), they must take action to become compliant (they must pay the full amount owed), or they must quit the agreement and surrender possession (terminate the tenancy and vacate the rental property). The Illinois Notice to Pay Rent or Quit is a demand letter used by landlords and property managers in Illinois to notify tenants that they are late with the rent payments and they must pay or get out. Illinois Notice to Pay Rent or Quit - What is it?