Composite rent treatment: inseparable lettings taxed as business or other income; separable shares allocated to house property and other heads. Tax treatment of composite rent turns on separability of lettings. If lettings are inseparable, the entire composite rent is taxed under 'Profits and gains of business or profession' or 'Income from other sources' and not under 'Income from house property.' If lettings are separable, the composite receipt must be allocated: the building's rent is chargeable under 'Income from house property' and the rent of other assets under 'Profits and gains of business or profession' or 'Income from other sources.'