Oregon’s Corporate Activity Tax catches many small business owners off guard because it’s based on gross receipts, not profit. Any business with Oregon commercial activity above $750,000 has registration and filing obligations, regardless of entity type. The tax rate is 0.57% on taxable commercial activity over $1,000,000, but businesses can reduce their burden significantly by choosing the right cost subtraction method – 35% of either labor costs or cost of goods sold. Quarterly estimated payments are required for most filers, and missing deadlines creates penalties separate from annual filing accuracy. Planning ahead in 2026 means reviewing subtraction options, tracking Oregon-sourced revenue cleanly, and registering before crossing the threshold rather than after. Perpetual CPA LLP in Beaverton, OR helps small businesses across the state get this right.