If, after an audit of the tax return, the Department determines that the tax is more than the amount shown on the return, the Department will mail to the company a deficiency assessment for taxes due. Interest and penalty shall be imposed if a company fails to pay an installment when due, or estimates a tax that is less than 90 percent of the amount due for the current taxable year and less than 110 percent of the tax paid for the prior taxable year. Failure to file a return or pay the tax when due will result in the imposition of interest and penalty. A company may appeal an assessment within 30 days of the date of mailing of the assessment by applying in writing to the Department for a revision or abatement of amounts due. The company may request an informal hearing on the issue. Following the application or hearing, the Department will take appropriate action and issue a final assessment to the company. A company may appeal a final assessment to the Maryland Tax Court within 30 days after the date of mailing of the final assessment.