Japan Bank Code Lookup: Full Zengin (全銀協) API for AI Agents

Japanese payroll, B2B transfers, and KYC flows all depend on Zengin (全銀協) bank codes — a 4-digit code per bank plus a 3-digit branch code. The data is published by the Japanese Bankers Association but only as flat files. Torify wraps the full 1,152 banks + every branch as a single REST API.

Endpoint

GET https://torify.dev/v1/bank/lookup

Parameters

Name	Type	Required	Description	Example
`bankCode`	string	Yes	4-digit Zengin bank code	`0001`
`branchCode`	string	No	3-digit branch code (optional)	`001`

Response example

{
  "ok": true,
  "data": {
    "bankCode": "0001",
    "bankName": "みずほ銀行",
    "bankNameEn": "Mizuho Bank",
    "bankKana": "ミズホ",
    "branchCode": "001",
    "branchName": "東京営業部",
    "found": true
  }
}

Code examples

curl

curl "https://torify.dev/v1/bank/lookup?bankCode=0001"

TypeScript (x402-fetch)

import { wrapFetchWithPayment } from 'x402-fetch';
import { privateKeyToAccount } from 'viem/accounts';

const account = privateKeyToAccount(process.env.PRIVATE_KEY as `0x${string}`);
const fetchWithPayment = wrapFetchWithPayment(fetch, account);

const res = await fetchWithPayment(
  'https://torify.dev/v1/bank/lookup?bankCode=0001'
);
const data = await res.json();
console.log(data); // { ok: true, data: { ... } }

Python (requests)

import requests

# Free MCP tier (no auth) or API key (X-API-Key header)
res = requests.get(
    "https://torify.dev/v1/bank/lookup?bankCode=0001",
    headers={"X-API-Key": "your_torify_pro_key"}
)
print(res.json())

Use cases

Global payroll provider validating Japanese bank transfer details

Deel, Remote.com, Rippling pay Japanese employees via Zengin transfer. Validating bank + branch + account format before submission prevents costly transfer reversals.

Fintech KYC verifying customer bank accounts

When a Japanese customer enters a 4-digit bank code, the app instantly auto-fills the bank name and provides a branch picker — using Torify's `/v1/bank/lookup` + `/v1/bank/search?bankCode=XXXX`.

AI agent processing Japanese banking documents

Agents reading invoices or remittance forms with Zengin codes can resolve them to human-readable bank/branch names without maintaining a local Zengin database.

Edge cases & gotchas

Bank code 9900 is ゆうちょ銀行 (Japan Post Bank) for transfer purposes. The "regular" Japan Post Bank account uses 0397.
Branch codes can be reused across banks (e.g., 001 is "本店" for multiple banks). Always validate bankCode + branchCode together.
Some smaller credit unions and JA banks share codes — Torify includes all 1,152 institutions including 信用金庫 (shinkin) and JA banks.

Related endpoints

/v1/bank/search — Japan Bank Search: Zengin Bank & Branch Name API
/v1/bank/list — Japan Financial Institution List API
/v1/bank/transfer/validate — Japan Bank Transfer Validation API
/v1/yucho/convert — ゆうちょ → Bank Transfer Account Conversion API

← All 36 endpoints

Pricing

$0.02 per call via x402 (USDC on Base). Or use a Pro API key ($49/mo, 10,000 calls/month).

View pricing Code examples ↗