Clarifying the scope of the investment income business and occupation tax deduction.

HB 1998 clarifies which investment income businesses can deduct when calculating Washington state's business and occupation tax. It specifically allows deductions for income from investments like stocks, bonds, and interest between related entities (if under 5% of gross receipts), while excluding income from banking, lending, factoring, or credit extensions. The bill defines key terms like "banking business" and "investment" to resolve recent legal uncertainty after a court case created confusion about deductible income. It applies retroactively to past tax years but does not create new refund rights for taxes already paid.