Our main business (Company A) made a loan to a start-up (Company B) with a shared director. The start-up hasn't made a profit and we have been advised to write off the loan. We have been told this would attract corporation tax. Is this correct? And if so, is there a more tax-efficient method of dealing with it? 

Arthur Weller replies:  

If Company A and Company B are under common control, the write-off of this loan between them should not produce any tax consequences for the companies – see HMRC’s Corporate Finance Manual at CFM35320.