Appellate Practice Attorney serving New York, NY
Your question is complicated and may depend on who you're fighting with. If the owner was trying to get you out, and your only basis for occupancy was a forged sublease, you would probably lose. The only chance I can see is if you could show that the owner knew or should have known about the forged sublease and went along with it, thereby ratifying it. This is a longshot. However, if you ask the owner to approve the sublease now, he/she/it could do so and it would be as if he/she/it had signed it originally, with no forgery. Your mother-in-law, the forger, can't claim any benefits from the forgery. Even if you don't get the owner to ratify the sublease, your mother-in-law can't resist eviction by attacking her own forgery - the fake won't give you any rights against the owner, whose signature was forged, but it is valid as against your mother-in-law.
Answered on Nov 06th, 2018 at 2:48 PM