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Quickstart

Send a sales tax calculation from your server and read the result.

Create an API key
Open API keys in your dashboard to create one. New here? Create an account and API key. Keep the key on your server.
Choose an example
Use cURL, or install the Node.js or Python SDK. This example calculates a CAD 100 SaaS sale in Ontario.
Send the request
Keep the calculation ID and request ID with your record. Check outcome before using the amounts.

Set your API key

Set SALESTAX_API_KEY in your server environment. Keep secret keys out of browser and mobile code.

Environment variableShell

export SALESTAX_API_KEY="stca_your_key"

Send a calculation

This example uses a CAD 100 transaction in Ontario. Replace its details with the facts for your transaction.

Request

Shell

curl --request POST \
  --url "https://api.salestaxcalculatorapi.com/v1/calculations" \
  --header "Authorization: Bearer $SALESTAX_API_KEY"
  --header "Content-Type: application/json" \
  --header "Idempotency-Key: order-1001-calc" \
  --data '{"reference":"order-1001","transaction_date":"2026-08-29","currency":"CAD","tax_behavior":"exclusive","billing_event":"subscription_start","seller":{"country":"CA","channel_role":"direct_legal_supplier","registrations":[{"country":"CA","state":"ON","type":"gst_hst","effective_from":"2026-01-01"}]},"customer":{"type":"consumer","address":{"country":"CA","state":"ON","postal_code":"M5V 2T6"}},"lines":[{"reference":"subscription","amount":"100.00","quantity":"1","tax_code":"saas"}]}'

Read the response

HTTP 201 means the API saved the calculation. Check outcome before using tax or total.

201 CreatedJSON

{
  "id": "calc_01J6A3S8Z6K4M6T2Y2W9M5X8Q0",
  "object": "calculation",
  "reference": "order-1001",
  "outcome": "calculated",
  "currency": "CAD",
  "subtotal": "100.00",
  "taxable_amount": "100.00",
  "tax": "13.00",
  "total": "113.00",
  "lines": [
    {
      "id": "line_01J6A3T26X8BS4Y8XJKZ0H8F3P",
      "reference": "subscription",
      "outcome": "calculated",
      "subtotal": "100.00",
      "taxable_amount": "100.00",
      "tax": "13.00",
      "total": "113.00",
      "explanation": "Tax was calculated for this sale."
    }
  ],
  "explanation": "Tax was calculated for this sale.",
  "request_id": "req_01J6A3RZ1HT2K3W2X8R7P1J4C9",
  "created_at": "2026-08-29T12:00:00Z"
}

For this example, outcome is calculated, tax is CAD 13.00, and total is CAD 113.00.