The preceding sentence applies only if the underpayment for the carryback year exceeds the applicable dollar limitation ($5,000, or $10,000 for most corporations). See Example 3 in paragraph (d) of this section.
Example. Partnership P has two partners, individuals A and B. P claims a $40,000 basis in a depreciable asset which, in fact, has a basis of $15,000. The determination that there is a substantial valuation misstatement is made solely with reference to P by comparing the $40,000 basis claimed by P with P's correct basis of $15,000. However, the determination of whether the $5,000 threshold for application of the penalty has been reached is made separately for each partner. With respect to partner A, the penalty will apply if the portion of A's underpayment attributable to the passthrough of the depreciation deduction, when aggregated with any other portions of A's underpayment also attributable to substantial or gross valuation misstatements, exceeds $5,000 (assuming there is not reasonable cause for the misstatements (see§ 1.6664-4(c) ).
26 C.F.R. §1.6662-5