Hello, I'm Keith and happy to help you with your question.
It is bad news I am afraid. The written off loans to the company do create a Corporation Tax (CT) liability. Your accountant is correct, the write off is a non-trading profit which effectively makes an overall profit in the company's accounts for the relevant year. You add that to the trading profit to arrive at the profit for CT purposes. Any losses brought forward from the year(s) before may be written off against this as can any true trading loss in that year, but I suspect that the company is in for a heavy CT bill. Under the circumstances HMRC may be willing to assist in staged payments, there being little point in their driving the organisation to the wall for a few bob when they might get a lot more in the long term. They will, of course, be entitled to interest and may raise penalties also. However, it may be more economical to put the company into receivership as insolvent and transfer your trade to a new organisation. There is, of course, the adverse publicity this may generate to consider not to mention that, if you have taken moneys out of the company, you may have unwittingly created a fraudulent preference when large sums were due elsewhere (ie to HMRC). I do not enter this moral maze!
Fortunately VAT does not come into these transactions, they are outside the scope of the tax.
Sorry to be the purveyor of such gloomy news.