If the City Treasurer has reason to believe that the tax imposed by this article is insufficiently returned by a taxpayer, either because the taxpayer has failed or refused to make a return, or has made an incomplete return, or has made a return which is deficient or otherwise erroneous, he may proceed to determine the amount of the tax for which the taxpayer is liable. The City Treasurer may make such audits and investigations and take such evidence and testimony as may be necessary for the purpose of his investigation.
As a result of his investigation, the City Treasurer may assess the amount of the tax which he finds to be due. After ten days' notice in writing to the person assessed, he may proceed to collect the tax.
(1981 Code Sec. 781.05)