(1) If a taxpayer or employer fails or refuses to make a return or payment as required, in whole or in part, or if the administrator or the department has reason to believe that a return made does not supply sufficient information for an accurate determination of the amount of tax due, the administrator or the department may obtain information on which to base an assessment of the tax. The administrator or the department may examine the books, papers, and records of any person, employer, taxpayer, or agent or representative of any person, employer, or taxpayer or audit the accounts of any person, employer, or taxpayer or any other records pertaining to the tax, to verify the accuracy and completeness of a return filed, or, if no return was filed, to ascertain the tax, withholding, penalties, or interest due under this ordinance.

    (2) The administrator or the department may examine any person, under oath, concerning income which was or should have been reported for taxation under this ordinance, and for this purpose may compel the production of books, papers, and records and the attendance of all parties before him or her, whether as parties or witnesses, if he or she believes those persons have knowledge of the income. For a city that has entered into an agreement with the department pursuant to section 9 of chapter 1, all of the following apply to implement this section:

    (a) The department shall send to the taxpayer or employer a letter of inquiry stating, in a courteous and unintimidating manner, the department's opinion that the taxpayer or employer needs to furnish further information or owes taxes to the city, and the reason for that opinion. A letter of inquiry shall also explain the procedure by which the taxpayer or employer may initiate communication with the department to resolve any dispute. A letter of inquiry may be served on the taxpayer in any manner determined appropriate by the department. This subdivision does not apply in any of the following circumstances:

    (i) The taxpayer or employer files a return that shows a tax due and fails to pay that tax.

    (ii) The deficiency resulted from an audit of the taxpayer's or employer's books and records by the city or the department.

    (iii) The taxpayer or employer otherwise affirmatively admits that a tax is due and owing.

    (b) If the dispute is not resolved within 30 days after the department sends the taxpayer or employer a letter of inquiry or if a letter of inquiry is not required under subdivision (a), the department, after determining the amount of tax due from a taxpayer or employer, shall give notice to the taxpayer or employer of the department's notice of intent to assess the tax. The notice shall include all of the following:

    (i) The amount of the tax the department claims the taxpayer or employer owes.

    (ii) The reason for the deficiency.

    (iii) A statement advising the taxpayer or employer of his or her right to file a protest and to a hearing with the department as provided under section 84.