UK Landlord Forum / Life

I just decided to give a tenant notice to quit. I had sent him a new tenancy agreement for the six months from 31st July but he didn't return it so he is on a periodic tenancy. As such I can give him two months notice from the 30th November. My question is what if he decides to sign the six month agreement I sent him in July and send it to me? If I'm bound by it then I can't give him notice until 31st January. Thanks.