The self-assessment regime means that the Tax Department need not routinely make assessments. An assessment may be made where it is discovered there has been a loss of tax or an overpayment of a tax credit in respect of a Reimbursable Tax Loss under Part 16. Discovery assessments may not be made where information has been provided timeously. Assessments may only be made within specified time limits. Relief is provided for where a QFC Entity has overpaid tax due to an error or mistake in a return.