Legal Question in Real Estate Law in Illinois

Insufficient information, and "void" may not be the right word. Let's say husband and wife applied for the lease with joint credit, the landlord relied on the marital status and credit information, and prepared a lease and gave it to both to sign; that is an "offer". If husband or wife now won't sign the lease but one does and turns it back to the landlord saying the other won't sign, that is a "counteroffer". But it doesn't make the lease, as prepared, void. Instead it would then be up to the landlord to decide whether to accept the counteroffer, and if the landlord then signs off knowing the other won't sign, the lease would be binding between the signing parties although if I was the landlord then to avoid any question in the future I would strike out the name of the party not signing but keep that party's name on as a "permitted occupant" or something like that. There are other variations on this theme depending on whether the prospective lessees are not married.