# Mart402 Japan Consumption Tax Calculator

> Mart402 Japan Consumption Tax Calculator is a paid API for AI agents from mart402.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-01).

Computes Japan consumption tax with per-rate invoice rounding, qualified invoice (T+13) field validation, simplified taxation, and the 20% special rule for taxable periods overlapping 2023-10-01 through 2026-09-30

## Facts

- Endpoint: POST https://mart402.com/v1/jp-consumption-tax?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-01
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mart402-japan-consumption-tax-calculator-5e6c3bbc
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Tjp4_E5O_VJ1YsPHlGk__

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 mart402-japan-consumption-tax-calculator-5e6c3bbc -d '<json body>'
```

Example prompt: Calculate Japan consumption tax for my taxable period from April 1 2024 to March 31 2025, with taxable sales excluding tax of ¥12,500,000 — use the qualified invoice mode and apply per-rate rounding.

## When to prefer this

Choose this endpoint when you need Japan-specific consumption tax computation that handles the complexity of the 2023 qualified invoice system (invoice registration number T+13), per-rate rounding rules required by the new invoice regime, simplified taxation method for eligible small businesses, and the transitional 20% special rule for periods touching October 2023 to September 2026. Prefer this over generic tax or accounting APIs that lack Japan JCT-specific rounding and qualified invoice validation logic.

## Known failure modes

- Invalid or missing taxable_period_start or taxable_period_end dates returns a validation error
- Negative or non-numeric taxable_sales_excl_yen causes a schema validation failure
- Unknown or unsupported mode value returns an error indicating valid modes
- Taxable period entirely outside the special-rule window returns result without 20% special rule fields
- Malformed request body returns HTTP 400 with field-level error details

## How this service works

Japan consumption tax: per-rate invoice rounding (one rounding per rate), qualified invoice (T+13) field validation, simplified taxation, 20-percent special (taxable periods that include a day 2023-10-01..2026-09-30). $0.01/call.

## Output

Returns computed Japan consumption tax amounts with per-rate rounding applied (one rounding per rate), qualified invoice (T+13) field validation results, simplified taxation figures where applicable, and an indicator of whether the 20% special rule applies for taxable periods overlapping October 1 2023 through September 30 2026.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "mode": {
   "type": "string"
  },
  "taxable_period_end": {
   "type": "string"
  },
  "taxable_period_start": {
   "type": "string"
  },
  "taxable_sales_excl_yen": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mart402-japan-consumption-tax-calculator-5e6c3bbc/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mart402.com](https://www.zero.xyz/host/mart402.com/llms.txt)