Regulation 34 Manner of calculation or estimation of earnings.
Where the Secretary of State cannot readily ascertain the amount of earnings in any tax week or is satisfied that records of earnings in any tax week have not been maintained or retained or are otherwise unobtainable, he may—
(a)
compute, in such manner as he thinks fit, an amount which shall be regarded as the amount of earnings; or
(b)
take their amount to be such as he may specify in the particular case.