About

An address typically belongs to multiple taxing jurisdictions: a country, state or province, county, city, and district. A Geo Code represents the unique combination of these jurisdictions and is one of the primary factors in determining which tax rules apply to a transaction.

GTD derives Geo Codes from ship-from or ship-to addresses using standard address elements.

Use the Geo Code endpoints to get Geo Codes in advance and include them in your transaction requests. You can also let Tax Determination determine Geo Codes during tax calculation, but pre-determining Geo Codes reduces processing time during calculations. It will, however, require you to cache or store the Geo Code values. Use POST.../geoCode/single for real-time transactions with clear addresses. Use POST.../geoCode/multiple when addresses span multiple jurisdictions.

You can use the tjc/reverseSearch endpoint to convert a Tax Jurisdiction Code (TJC ID) and 5-digit ZIP code into a full 9-digit ZIP code (ZIP+4) for filing purposes. This is the reverse of geocoding.

Example use cases

Get Single Geo Code (/single)

Validate customer shipping address in Kivalina, Alaska. It returns Geo Code "1294" for tax calculation.

Get Multiple Geo Codes (/multiple)

Address in Aurora, CO spans multiple counties. It returns 3 possible jurisdictions (Geo Codes 8488, 8244, 15427) and allows you to select one.

Batch Address Validation

Import 10,000 customer records to validate and standardize addresses, pre-calculate Geo Codes for faster future tax calculations.

Get ZIP9 codes

You have TJC ID "8488" and ZIP code "80010." It returns ZIP+4 "800101234" so you can use "80010-1234" when filing.