# Duty / Value Calculation API

> Calculate applicable stamp duty for a given article, state and transaction value. Endpoint: `POST https://api-b2b.stampmitra.in/v1/estamp/duty/calculate`.

API fee: ₹5 per successful call, pay-as-you-go (lower on Growth and Scale). State procurement fee and stamp duty are quoted per order. Sandbox keys are free. Prices exclude 18% GST.

- HTML docs: https://developer.stampmitra.in/docs/estamp/estamp-duty-value
- Product page: https://developer.stampmitra.in/products/estamp-duty-value
- Pricing: https://developer.stampmitra.in/pricing
- Authentication: https://developer.stampmitra.in/docs/auth

## Calculate authoritative e-Stamp duty + service charges

`POST https://api-b2b.stampmitra.in/v1/estamp/duty/calculate`

Required scope: `estamp.duty.calculate`

Runs the one authoritative pricing calculation; the response amount is never recalculated or overridden client-side. Requires the `estamp.duty.calculate` scope. Metered against your fulfilment wallet.

### Parameters

- `Authorization` (header, required): Bearer <api-key> (e.g. sk_test_... in sandbox, sk_live_... in production). The x-api-key header is also accepted.
- `stateCode` (string, required): State code, e.g. MH.
- `articleCode` (string, required): Stamp article code from the articles lookup.
- `stampDutyAmount` (number, required): Stamp duty amount to calculate charges for; must be positive.
- `districtCode` (string, optional): District code, where the state needs one.
- `sroValue` (string, optional): Sub-registrar office value, where the state needs one.
- `doorstepDelivery` (boolean, optional): Whether doorstep delivery is requested.
- `couponCode` (string, optional): Coupon code to apply.
- `masterDataVersion` (integer, optional): Master-data version the caller last read.

### Request example

```json
{
  "stateCode": "MH",
  "articleCode": "5",
  "stampDutyAmount": 500
}
```