structural:expansion, structural:summarization
Insolvency Act 1986

123.-(1) A company is deemed unable to pay its debts --- (a) if a creditor (by assignment or otherwise) to whom the company is indebted in a sum exceeding £750 then due has served on the company, by leaving it at the company's registered office, a written demand (in the prescribed form) requiring the company to pay the sum so due and the company has for 3 weeks thereafter neglected to pay the sum or to secure or compound for it to the reasonable satisfaction of the creditor,... (2) A company is also deemed unable to pay its debts if it is proved to the satisfaction of the court that the value of the company's assets is less than the amount of its liabilities, taking into account its contingent and prospective liabilities...