GET /jurisdiction/zip/{zip_code} — Resolve by ZIP

Use this endpoint to check the rounding rule for any location before processing a transaction. It returns the full resolution chain — city, then county, then state, then federal default — so you always get the most locally specific rule that applies. The database covers 33,791 U.S. ZIP codes mapped to their state, county, and city.

Endpoint

GET https://api.centsless.org/api/v1/jurisdiction/zip/{zip_code}

Authentication

All requests require an x-api-key header. Keys are issued per role — merchant, auditor, or admin.

Path parameters

string

required

The 5-digit U.S. ZIP code to resolve. Example: 85001

Code example

curl https://api.centsless.org/api/v1/jurisdiction/zip/85001 \
  -H "x-api-key: YOUR_API_KEY"

Example response

{
  "jurisdiction_id": "US-AZ",
  "jurisdiction_level": "state",
  "rounding_mode": "swedish_rounding",
  "enforcement": "mandatory",
  "legislation": "AZ HB 2938",
  "status": "enacted",
  "effective_date": "2025-01-01",
  "notes": "Swedish rounding required for all cash transactions statewide.",
  "source_url": "https://leginfo.example.gov/az/hb2938"
}

Response fields

string

Jurisdiction identifier. Example: US-AZ

string

The level in the resolution hierarchy where the rule was found. One of: federal, state, county, city

string

The rounding algorithm that applies at this location. One of: swedish_rounding, mandatory_round_down, mandatory_round_up, symmetrical_rounding, nearest_nickel, nearest_cent, nearest_dime, none

string

How strictly the rule applies. One of: mandatory, permissive, voluntary, none

string

The bill or regulation that enacted this rule. Example: AZ HB 2938

string

Legislative status. One of: enacted, pending, proposed, failed, no_legislation

string

The date the rule took effect, in ISO 8601 date format.

string

Additional context about the rule or its scope.

string

URL to the authoritative legislative source.

You do not need to make a separate lookup before processing a transaction. Pass zip_code directly in your /transaction request body — the engine resolves the jurisdiction and applies the correct rounding rule automatically.

Overview

Transactions

Jurisdiction

Tipping

Compliance & Audit

GET /jurisdiction/zip/{zip_code} — Resolve by ZIP

Endpoint

Authentication

Path parameters

Code example

Example response

Response fields

​Endpoint

​Authentication

​Path parameters

​Code example

​Example response

​Response fields

Endpoint

Authentication

Path parameters

Code example

Example response

Response fields