From 1 October 2019 a marketplace facilitator meeting either test, counting facilitated and direct sales together, registers and collects Maryland sales and use tax on each retail sale it facilitates. A marketplace seller whose sales are all through a facilitator need not register; one that also sells directly registers as an out-of-state vendor if its direct sales meet the test.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.