# UK Stamp Duty Land Tax (SDLT) Calculator

> UK Stamp Duty Land Tax (SDLT) Calculator is a paid API for AI agents from web-production-18a32.up.railway.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Calculates UK Stamp Duty Land Tax owed on a property purchase, applying first-time buyer relief, additional property surcharges, and non-resident surcharges at October 2024 rates.

## Facts

- Endpoint: POST https://web-production-18a32.up.railway.app/stamp-duty
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/uk-stamp-duty-land-tax-sdlt-calculator-9ddc9b7f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_cCk7oP44j7T3uJ178QGQs

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability uk-stamp-duty-land-tax-sdlt-calculator-9ddc9b7f -d '<json body>'
```

Example prompt: How much stamp duty will I owe on a £450,000 property in England if I'm a first-time buyer and it will be my only home?

## When to prefer this

Use this endpoint when you need to compute UK Stamp Duty Land Tax for a residential property purchase in England or Northern Ireland, especially when buyer status (first-time, additional property, non-resident) affects the calculation. Prefer over generic tax calculators when you need October 2024 rate accuracy including the updated 5% additional property surcharge.

## Known failure modes

- Missing or invalid price (negative or non-numeric) returns a validation error
- Price below SDLT threshold returns zero tax
- Conflicting flags (e.g. first-time buyer + additional property) may yield unexpected results
- Non-boolean values for flag fields return a schema validation error

## How this service works

UK Stamp Duty Land Tax (SDLT) calculator with first-time buyer relief and surcharges.

## Output

The calculated SDLT liability in GBP, including any applicable first-time buyer relief reduction or surcharge additions for additional properties or non-UK residents, based on the October 2024 rate bands.

## Example request

```json
{
 "price": 450000,
 "is_non_resident": false,
 "is_first_time_buyer": true,
 "is_additional_property": false
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "price": {
   "type": "number",
   "minimum": 0,
   "description": "Property purchase price in GBP."
  },
  "is_non_resident": {
   "type": "boolean",
   "description": "Non-UK residents pay an extra 2% surcharge."
  },
  "is_first_time_buyer": {
   "type": "boolean",
   "description": "First-time buyers get relief on properties up to £625,000."
  },
  "is_additional_property": {
   "type": "boolean",
   "description": "Second homes / buy-to-let pay a 5% surcharge (Oct 2024 rates)."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/uk-stamp-duty-land-tax-sdlt-calculator-9ddc9b7f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from web-production-18a32.up.railway.app](https://www.zero.xyz/host/web-production-18a32.up.railway.app/llms.txt)