Readers’ forum: Interest earned

My understanding from reading HMRC’s Property Income Manual at PIM1030 is that joint owners of property who are unmarried can choose how the rental profits are shared for tax purposes. This is after taking any allowable expenditure into account including the relevant proportion of loan interest.

My questions are as follows. First must the entitlement to the basic rate income tax deduction (derived from the loan interest that cannot be claimed against the income) follow the chosen profit share split? Second and alternatively is entitlement to the tax relief for loan interest determined by how much interest was actually paid by the individual in question when the loan is in the name of just one of the joint owners? Finally if a property is owned beneficially by an unmarried couple but the...