In an unusual decision by the Court of Appeal in Driver v Air India Ltd  (EWCA Civ 830), it was held that where no contractual payment for overtime is specified, the law will imply a reasonable sum.
Mr Driver had been employed by Air India for 35 years. He transferred to a new contract that provided for rostered and ad hoc overtime, payment for which would be set out in company issued notices and circulars. No such notices or circulars were ever issued.
It was held that, although no notices or circulars were issued, the right to payment for ad hoc overtime was a contractual entitlement as Mr Driver's contract clearly contemplated payment for such overtime and he had been paid for it in the past. The Court of Appeal also held that where a contractual payment sum is not specified, the law will imply a reasonable sum.