Member states require sellers to source retail sales under Section 310 or 310.1. Where delivery needs a full street address, a seller exercises due diligence when it has the full address and five-digit zip code (from the order or its ordinary records) and it or its CSP standardises the address with the USPS look-up, CASS-certified software or other approved software, then matches it to the state's address records if any, else to the nine-digit zip records, else to five-digit records. Where delivery does not need an address, the seller must request (unless already held) the full address and five-digit zip code or the nine-digit zip code at the time of sale and follow the same matching order; a state may let the seller use only the five-digit zip code in its records or from the payment instrument. A seller that neither obtained nor requested the address uses the five-digit zip code in its records or from the payment instrument, without Section 306 relief. A request means an address field on the ordering page at least as prominent as other required fields, which may be pre-filled from the payment instrument or GPS location, never labelled optional (it may be labelled mandatory or as used to compute tax), though the seller need not reject an order lacking it. Once sourced to a state, the seller collects that state's applicable tax. The rules apply whether the product is tangible property, a digital good or a service, govern only the seller's collection duty (not the purchaser's use tax), and exclude watercraft and homes, non-transportation-equipment motor vehicles and aircraft (leases go to 310(C)), telecommunications and internet access (Section 314), florist sales and direct mail (Section 313).
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.