Howard Graham Wood placed the advert, promoting a debt arrangement, in Money Marketing in 1994.
An institute disciplinary tribunal found this contravened its code of professional ethics, which states members should not make cost comparisons with other accounting practices in promotional material.
Other complaints against Wood included undertaking work without a practising certificate and making misleading claims about debt arrangements. All were upheld.
The tribunal said Wood, from Okehampton in Devon, had admitted serious offences which could have led to his expulsion from the institute. But due to mitigating circumstances, it chose to impose a reprimand, and fine Wood #500 plus #500 costs.
Other penalties imposed by the institute included a #5,000 fine against David Reeves Carter of Kings Lynn, Norfolk, and a #2,500 fine imposed against Michael Francis Davies of Worthing.
Both were fined in relation to a joint audit. The appeal committee upheld the fines, imposed by a disciplinary tribunal in June, over weaknesses in the quality of the audit.
The disciplinary board also upheld five complaints against Alan Gillard, of Wells, Somerset, for failing to respond to institute enquiries about his handling of the tax affairs of a firm of vets.
Gillard admitted to the complaints, saying his practice management had become a nightmare as a result of staff difficulties, computer problems and an office move. He was reprimanded and fined #250 and charged costs of #300 for each complaint.
Complaints were also upheld against Sanjit Kumar Banerjee of Harrow, Middlesex. These related to mistakes and false claims in a set of accounts prepared by the defendant, and advice given to a company to declare a dividend which exceeded profits available for distribution. The tribunal ordered Banerjee be reprimanded, and imposed fines of #2,500 and #1,500 costs.
The investigation committee also made orders against Robert Goldie Ellis of Cardiff, John Charles Reid, also of Cardiff, Ketan Kumar Savjibhai Patel of Woking and George Stephen Murray of County Durham.