The protection afforded under 15 U.S.C. § 381 will be determined on a tax year by tax year basis. Therefore, if at any time during a tax year the taxpayer conducts activities within Arkansas that are not protected under 15 U.S.C. § 381, all income earned by the taxpayer attributable to Arkansas during such tax year will be subject to Arkansas income tax.
11.26 Ark. Code R. 51-702