a Tenant has just moved into a house share a week ago, since then another tenant has moved out so my new Tenant would like to change rooms. I can easily do the new new tenancy agreement but does the deposit need to be returned although the price will stay the same and has only been protected for one week?
If the tenant has a room only contract then check with the scheme whether it has to be refunded and taken again. You would certainly have to serve the new deposit prescribed information as well as all the other documents (EPC, How to Rent, GSC, EICR) and as you say, a new tenancy agreement after surrendering the old tenancy.
If its a joint tenancy you don’t have to do anything.