The Commissioner of Customs and Excise held the respondents, both licensed clearing agents, liable under s 99(2)(a) of the Customs and Excise Act 91 of 1964 for unpaid customs duties and charges relating to goods cleared in Durban for export to Mozambique. An investigation revealed large-scale fraud involving counterfeit customs stamps and signatures on returned bills of entry, with the result that certain goods never left the common customs area. Conlog was involved in 41 such transactions and Renfreight in two. Although the respondents acted as agents for principals who diverted the goods, the Commissioner concluded that they had not taken all reasonable steps to prevent the non-fulfilment of their principals’ obligations and therefore remained liable. The respondents successfully reviewed these decisions in the Transvaal Provincial Division, and the Commissioner appealed to the Supreme Court of Appeal.