US sales tax STATE-LEVEL base rates for the 50 states + DC, as statutory percent. ?state=CA for one state, omit for all. Returns the state-only rate, any mandatory statewide local add-on (CA/UT/VA) and their sum. STATE BASE RATE ONLY — optional city/county/district rates are EXCLUDED and can add several points; not tax advice. Compiled from state statutes, cross-checked against two dated published trackers (asOf field included).