1.26 Ark. Code R. 18-404
A taxpayer may file a protest based upon a Notice of Tax Adjustment and need not wait until a Notice of Proposed Assessment is received.
Taxpayers must protest a Notice of Proposed Assessment in writing, within thirty (30) days of service of the notice. The protest must include the taxpayer's grounds for protesting the assessment. The grounds should be explained as thoroughly as possible to enable the Department to better understand the taxpayer's position. If the thirtieth (30th) day falls on a Saturday, Sunday or legal holiday, the next succeeding day which is not a Saturday, Sunday or legal holiday is considered to be the thirtieth (30th) day for purposes of meeting the prescribed time period in which to file the protest.
1.26 Ark. Code R. 18-404