Tax Deductible

Tax allowable and tax-deductible mean the same thing - that the item can be subtracted in arriving at the taxable profits. Debt interest is tax allowable. I do suggest that you watch my lectures because the fact that interest is tax allowable is fundamental to so many of the exercises in Paper FM (such as cost of capital calculations; Modigliani and Miller; use of the CAPM asset beta formula; etc..)