If the Indiana Department of Revenue (“IDR”) reasonably believes that a taxpayer has not reported the proper amount of tax due, then, based on the best information available, it shall make a proposed assessment of the amount of the unpaid tax. The IDR shall send the taxpayer a Notice of Proposed Assessment (“AR-80”) via the United States mail.
A taxpayer may challenge the proposed assessment, by filing a written protest (“Protest”), with the IDR, within sixty (60) days of the date of the AR-80. The right to file a Protest is waived if the taxpayer does not respond at the AR-80 stage.
If the taxpayer does not respond at the AR-80 stage, then Indiana law requires the IDR to commence the collection process.
Indiana Code §6-8.1-5-1
Indiana Department of Revenue Tax Practitioner Resource Packet