765 ILCS 745/7
Current through Public Act 103-593
If the tenant shall fail to sign a written lease which has been signed and tendered to him by the owner and shall further provide the owner with a rejection in writing of such offer, the tenant's continuation of possession and payment of rent without reservation shall constitute an acceptance of the lease with the same effect as if it had been signed by the tenant.
765 ILCS 745/7