If the agent refused to sign, it would imply that they regard your tenancy as remaining in place.
Never underestimate the ignorance of agents.I have never heard of an old contract needing to be surrendered officially, we have had many replacement tenants in the house and this has never been mentioned by the agents before
If a replacement tenancy is granted to the same tenant for the same rental property, then the replacement does indeed automatically surrender the previous tenancy. It's called surrender and regrant.I assumed that a new contract automatically rendered the old one obsolete?
If a new tenancy is granted to a different tenant (e.g. to T1/T2/T4 not T1/T2/T3) for the same rental property, then the replacement does not automatically surrender the previous tenancy, but, as I said before, you can argue that there has been a surrender by operation of law.
But you're in a less than ideal position if things remain unformalized. For example, let's say the replacement T does a moonlight flit next week, and arrears build up. It's conceivable that the LL could pursue you for unpaid rent, submitting the 'old' joint tenancy contract to the court as evidence of your liability. You'd then have to prove to the court that there was a surrender of that tenancy by operation of law, so that you're no longer liable for rent.
Whereas if you get a formal Deed of Surrender executed, there's no question of your liability.
Thank for your advice.