St Albans is right, I think – subject to one condition, which is that we are talking about freeholders here and the claimant’s interest is recorded at the Land Registry.
An owner has always been defined in the 1987 Regs, and now in the 2006 Regs, as a person who is entitled to dispose of the fee simple, either alone or jointly with others (with or without their consent). This definition was designed to overcome the effect of a 1986 decision under the previous HB Regs (Sedgemoor DC ex p Weadon) in which a claimant was paying rent to other joint owners – as in Julian’s case.
The definition catches both tenants in common and joint tenants as far as I can see. But it must be the freehold – that is, in plain English, what the fee simple means.
So if this claimant is registered as a freehold owner, I would say she is caught by Reg 12(2)(c)