A complaint had been made to the institute by a former business associate.
Mr Moffat had co-invested with the complainant in two companies and over the years, both took cash from one company without recording it as income from that business.
Both businesses were involved in a number of transactions in which Mr Moffat had a direct or indirect financial interest.
He told the tribunal his lapses occurred in a single set of circumstances where he failed to behave to his usual high standard.
Mr Moffat said he did not maliciously deceive anyone or act with the intention of securing gain for himself to the detriment of the complainant.
He submitted the appropriate penalty was censure.
However, the tribunal said in its decision that Mr Moffat's misconduct was on-going for a number of years and his conflict of interest related to a number of transactions over time, some of them substantial. Some of those transactions involved very substantial sums and many were not documented, the tribunal said.
Mr Moffat told the Northern Advocate he had failed to distinguish between his personal and professional position and, as a result, made an error of judgement.
With the exception of this complaint, Mr Moffat said he personally received no other formal complaint throughout his career as an accountant that began in 1996.
As a member of the Chartered Accountants of Australia and New Zealand (CAANZ), Spire was subjected to thorough reviews every three years.
"My own suspension from CAANZ in no way affects our ability to continue to provide the services we have promised to deliver to our clients, and as a continued member of CAANZ, our firm will operate with the same high service standards as we have done in the past," he said.