ZipTax Sales Tax Lookup

Setup

Set ZIPTAX_API_KEY env variable with your API key from https://platform.zip.tax (DEVELOP > API Keys).

Free tier gives 100 calls/month. Never share your API key publicly.

Quick Start

Address Lookup (most accurate)

curl -s "https://api.zip-tax.com/request/v60?address=200+Spectrum+Center+Drive+Irvine+CA+92618" \
  -H "X-API-KEY: $ZIPTAX_API_KEY"

Postal Code Lookup

curl -s "https://api.zip-tax.com/request/v60?postalcode=92618" \
  -H "X-API-KEY: $ZIPTAX_API_KEY"

Lat/Lng Lookup

curl -s "https://api.zip-tax.com/request/v60?lat=33.6525&lng=-117.7479" \
  -H "X-API-KEY: $ZIPTAX_API_KEY"

Workflow

1. Determine lookup type: address (best), lat/lng, or postal code
2. Use v60 (latest) for full jurisdiction breakdowns; use v10 for simple combined rate
3. Make GET request to https://api.zip-tax.com/request/v60 with auth header
4. Check metadata.response.code — 100 means success
5. Read taxSummaries[0].rate for total sales tax rate
6. Read baseRates array for state/county/city/district breakdown
7. Check service.taxable and shipping.taxable for service/freight taxability

Key Points

• Address > Postal code: Address gives one exact result; postal code returns all rates in that ZIP
• Auth: Header X-API-KEY or query param key
• Rate format: Decimal (0.0775 = 7.75%)
• Response code 100 = success; check metadata.response.code
• Metrics endpoint (/account/metrics) does not count against quota

Bundled Resources

• scripts/lookup.sh — CLI wrapper for quick lookups. Run with --address, --lat/--lng, --postalcode, or --metrics
• references/api-reference.md — Full API reference with all endpoints, response schemas, code samples, response codes, and SDK links. Read when you need endpoint details or response field definitions.