Iowa Administrative Code Title 701 — Department of Revenue
Iowa Admin. Code r. 701—204.4(423) — Allocation of bad debts
If a seller is entitled under Iowa Code section 423.21 to deduct bad debts owed to the seller and those bad debts consist of any sales price or purchase price upon which tax Revenue has been paid to the state of Iowa as well as a state or states other than Iowa, then allocation of the bad debt is allowed. The seller must support an allocation of the bad debts between Iowa and the other state or states through the proper accounting of its books and records.
Source: official text