I am planning to sell my rented house. Tenancy registered or so I thought. Notice given to tenants as due course. tenant seeking letter from PTRB , I presumed re confirming registered tenancy. No problem. Until I went into site to see how to go about it e.g. get the reference no for tenancy etc and see about needing to re-register after 4 years which I did not realise. Is this a a problem for me now? As far as I knew they were registered the whole time and I have had leases every year. Can I retrospectively re-register for 2 years ago? I have read that "new tenancies after Dec 2016 have new rights but the tenancy started in 2012. can I re-register them from Feb 2016 retrospectively? Otherwise I think this will change everything for me.