A marketplace facilitator that makes or facilitates $100,000 or more in Iowa sales must collect Iowa sales and local option tax on every taxable sale through its marketplace, whatever the marketplace seller's location or volume; Iowa does not allow facilitator and seller to agree that the seller collects. A seller whose Iowa sales are all through such a facilitator need not register; one with direct sales collects on those and deducts facilitated sales on its return.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.