Look up sales tax for an address, ZIP, or coordinates

GET

/v1/tax/{state}

• Production
• Local development

Returns the combined sales tax rate plus per-jurisdiction component breakdown for a U.S. location. Mutually exclusive input modes:

• address= — full street address. Most precise; resolves SPDs (Special Purpose Districts) that don’t surface from ZIP alone.
• location= — DoR-published place/city name. Returns the city’s rate without address-level SPD resolution.
• zip= — 5-digit ZIP. Returns the most common rate for that ZIP with a confidence envelope; ambiguous ZIPs may include multiple candidate rows.
• lat=&lng= — coordinates. Uses PostGIS polygon overlay where the state’s boundary data is loaded.

Historical queries. Pass as_of=YYYY-MM-DD to retrieve the rate in effect on that date. Supported on states with effective-period history (TX/CA/FL/WA/NY and all SST states); single-snapshot states (e.g., NM/MO/IL/CO/LA/AL/AZ/AK) return the current rate regardless of as_of.

Warnings. When the customer-supplied city name doesn’t match the resolved jurisdiction (e.g., address listed as ‘Frisco’ but actually in unincorporated Denton County), a place_input_mismatch warning is included in the response alongside the competitor-likely rate for comparison.

Parameters

Path Parameters

state

required

State

string

Query Parameters

location

Any of:

string

string

>= 1 characters <= 64 characters

null

null

Place/location name as published by the state DoR. For TX: Comptroller place name (e.g. Houston). For WA: city name (case-insensitive, e.g. Seattle) OR 4-digit location code (e.g. 1726).

zip

Any of:

string

string

/^\d{5}$/

null

null

5-digit US ZIP code. TX serves from the Census ZCTA-county relationship; WA returns 501 today (planned via Zip4Rates).

address

Any of:

string

string

>= 10 characters <= 200 characters

null

null

Full street address: ’, , ’. TX proxies the Comptroller’s locator API. WA returns 501 today (planned via WA DOR’s URL-API or local address-xref).

period

Any of:

string

string

/^\d{5}$/

null

null

Effective period code (5-digit YYYYQ). Defaults to the most recent loaded for the chosen state.

lat

Any of:

number

number

>= -90 <= 90

null

null

Latitude in WGS84 degrees. Required together with lng. WA serves via point-in-polygon against the LOCCODE shapefile; other states return 501 until their polygon ingestion lands.

lng

Any of:

number

number

>= -180 <= 180

null

null

Longitude in WGS84 degrees. Required together with lat.

as_of

Any of:

string

string

/^\d{4}-\d{2}-\d{2}$/

null

null

Historical effective date (YYYY-MM-DD). Returns the rate in effect on that date instead of today. Supported for SST states (which carry full effective-period history); ignored for states stored as a current snapshot.

Header Parameters

X-API-Key

Any of:

string

string

null

null

Responses

200

Successful lookup. Returns combined rate + components + resolved_place.

Response Get State Tax V1 Tax State Get

object

key

additional properties

any

400

Invalid input — missing required parameter or malformed value.

401

Missing or invalid X-API-Key / Authorization header.

404

State not supported, or address could not be resolved.

422

Validation Error

HTTPValidationError

object

detail

Detail

Array<object>

ValidationError

object

loc

required

Location

Array

msg

required

Message

string

type

required

Error Type

string

input

Input

ctx

Context

object

429

Monthly lookup quota exceeded for this API key’s tier.

503

Upstream geocoder or DoR locator unavailable (TX address mode only).