I've name-changed for this.
I'm renting privately and thought I needed to give only a month's notice to end my tenancy. On checking my tenancy agreement I discovered that it's supposed to be 90 days' notice O_o This is likely to cause problems because I'm in the process of buying a house.
However ... my tenancy agreement is signed only by me, not by my landlord. It's a 12-month assured shorthold tenancy agreement. I get on fine with my landlord and what tends to happen is that when the time comes around for the tenancy to be renewed, he asks me if I want to stay, then asks if I'd update the tenancy agreement and send it over. I send it to him with my signature, expecting him to sign too and return a copy to me, but he never does.
Does the fact that the landlord has not signed the tenancy agreement mean that it is invalid? If so, what is the status re me giving notice? I would ask Shelter but they're busy at the moment ...