---
title: "Calculate Tax"
method: POST
path: "/api/v1/payments/calculate-tax"
tags: ["payments"]
---

# Calculate Tax

`POST /api/v1/payments/calculate-tax`

Calculate tax for a project quote based on shipping address.

Uses the Stripe Tax Calculation API to compute destination-based
sales tax. The returned ``calculation_id`` must be passed to
``create-intent`` or ``purchase-order`` to attach tax to the payment.

Handles deposit quotes: if the quote requires a deposit, tax is
calculated on the deposit portion of each line item.

## Request body

- TaxCalculateRequest — Request body for calculating tax on a project quote.
  - `project_id` string, uuid, required
  - `shipping_address` ShippingAddressInput, required — Shipping address for tax calculation (destination-based taxation).
    - `line1` string, required
    - `line2` string, nullable
    - `city` string, required
    - `state` string, required — State name or two-letter code
    - `postal_code` string, required
    - `country` string — Country name or two-letter code

## Response `200`

Successful Response

- TaxCalculateResponse — Tax calculation result returned to the frontend.
  - `calculation_id` string, required
  - `subtotal` string, required
  - `tax_amount` string, required
  - `tax_rate` string, nullable
  - `total` string, required
  - `tax_breakdown` TaxBreakdownItem[], required
    - `jurisdiction` string, required
    - `rate` string, required
    - `amount` string, required
    - `tax_type` string, required

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.dev/prototyping/apis/prototyping-io-api.md) · [All operations](https://skmtc.dev/prototyping/apis/prototyping-io-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/prototyping/prototyping-io-api/revisions/f4a0079fbb57/schema)