On 30 September 2016, the company has trade receivables totalled £420,000 and the provision for doubtful debts from last year totalled £50,000. The company decides to write off debts totalling £30,000 and to adjust the provision to £45,000.

What is the amount of bad debts expense that should appear in the company's statement of profit or loss for the year ended 30 September 2016?