Stamp Duty Relief - Multiple Dwelling

ECB51

We moved into our home in February and have been bombarded with letters from various firms telling us we are due a refund on the stamp duty we paid as our home has two dwellings in their opinion. We have an annexe - bedroom, shower room, kitchen with its own front door but it can be accessed through our kitchen and we need to walk through it to get to the interior garage door. We currently use the space as a utility and guest area. £10k is the refund figure suggested which is substantial but I’m not sure if we qualify and I don’t want to open a can of worms regarding council tax. Gov.uk site is not totally clear on the subject.
Has anyone had similar letters and investigated further? 

Thank you 

lincroft1710

As regards Council Tax, from your description it appears the annex should have its own CT band.