Q. I run a small B&B which has three let bedrooms, my family uses the other two bedrooms of the property. How should I calculate how much of the property's running costs relate to the B&B business?

A. The answer is to include all of the property's running costs (power, rates and repairs) in your B&B accounts and take out, or 'disallow', an amount that relates to your family's use of the property. This is called a private use adjustment. In many towns the private use adjustment for B&Bs has been agreed locally with the Inspector of Taxes as a monthly or annual rate. However, from 1 April 2013 national rates of private use adjustment have been set by the Taxman as follows:

- 1 family member living in the premises: £350
- 2 family members living in the premises: £500
- 3 or more family members living in the premises: £650