UK: directors' liability for the company's debts - a tax deductible expense?

In small, private companies it is not unusual for directors to guarantee company debts.  In A Guarantor v HMRC Commissioners [2008] UKSPC 00703 a company's directors guaranteed the company debts and did so as a condition of a factoring agreement which the company had entered at a time of financial difficulty. One director (hereafter 'the taxpayer') resigned from office but nevertheless became liable under the guarantee. He argued that his liability was a tax deductible expense. HMRC disagreed and the taxpayer appealed: the appeal was heard in July by Special Commissioner Colin Bishopp. 

The general rule concerning the deductibility of employees' expenses is found in Section 336(1) of the Income Tax (Earnings and Pensions) Act (2003), which provides that a deduction is permitted if:

(a) the employee is obliged to incur and pay it as holder of the employment, and

(b) the amount is incurred wholly, exclusively and necessarily in the performance of the duties of the employment.

The taxpayer argued that conditions (a) and (b) were satisfied because he had a duty to maintain the company's solvency and, given that the company had exhausted all other possible sources of finance, his liability was incurred wholly and necessarily in the course of his employment. Special Commissioner Bishopp rejected the taxpayer's claim, agreeing with the majority of arguments advanced on behalf of HMRC including the fact that liability arose after the taxpayer's employment had ended (and was not, therefore, incurred in the performance of the employment). The Special Commissioner did, however, observe (at para. [12]): "Mr Smith's argument [on behalf of HMRC] that the payment is disqualified for relief because not every company director is obliged to give a personal guarantee for the company's debts may well overstate the position" (para. [12]).