๐ Japan & Korea Official Tax Revision Calendar & Government Source Registry
Tax brackets and social insurance rates change throughout the year. HonsMoney centralizes all statutory rates, caps, and deductions inside audited rule modules (src/rules/2026/jp.mjs and kr.mjs) and verifies them monthly and quarterly against official government publications.
๐๏ธ ๐ฏ๐ต ์ผ๋ณธ (Japan) โ 1์ ~ 12์ ์ฐ๊ฐ ์ธ๊ธยท์ ๊ณ ยทํ๊ธ ์ผ์
๐ 1์ (1ๆ) 2๊ฑด
Having a registered address in Japan on Jan 1 triggers Resident Tax billing starting in June.
Final quarterly installment deadline for residents paying via city hall slips.
๐ 2์ (2ๆ) 1๊ฑด
Reclaim overpaid Column B (ไนๆฌ) tax, medical deductions, or dividend tax credits via e-Tax.
๐ 3์ (3ๆ) 2๊ฑด
Updated prefectural health insurance rates take effect from March coverage (April paycheck).
Mandatory filing and payment deadline if you owe tax (refund-only claims can be filed for 5 years).
๐ 4์ (4ๆ) 1๊ฑด
Overtime worked paid in Apr, May, and Jun raises your health and pension bracket from September.
๐ 5์ (5ๆ) 1๊ฑด
Check your Resident Tax notice to verify dependent deductions and Furusato Nozei credits.
๐ 6์ (6ๆ) 1๊ฑด
Second-year residents see Resident Tax deducted for the first time on their June payslip.
๐ 7์ (7ๆ) 0๊ฑด
์ ๊ธฐ ์ ๊ณ ยท๊ฐ์ ์ผ์ ์์
๐ 8์ (8ๆ) 1๊ฑด
Second quarterly installment deadline for Ordinary Collection Resident Tax.
๐ 9์ (9ๆ) 1๊ฑด
Your updated Health Insurance and Welfare Pension deductions take effect starting with September coverage.
๐ 10์ (10ๆ) 1๊ฑด
Prefectural minimum wages increase in October, and Year-End Tax insurance certificates begin arriving by mail.
๐ 11์ (11ๆ) 1๊ฑด
Submit your 3 Year-End Tax Adjustment forms and overseas dependent remittance proofs to HR.
๐ 12์ (12ๆ) 1๊ฑด
Year-end tax refunds arrive in Dec payroll. Leaving Japan before Dec 31 avoids next yearโs Resident Tax.
๐ ๐ฏ๐ต ์ผ๋ณธ (Japan) โ ์๋ณยท๋ถ๊ธฐ๋ณ ์ธ๋ฒยท๋ณดํ๋ฃ์จ ์ ๊ธฐ ์ ๊ฒ ์ผ์
| ์ / ๋ถ๊ธฐ | ๊ตญ๊ฐ | ์ ๊ฒ ๋ฐ ๊ฐ์ ๋ฐ์ ํญ๋ชฉ | ๊ท์น ํ์ผ ์์น |
|---|---|---|---|
| 1ๆ (Q1) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: New year Withholding Tax Table takes effect / ๐ฐ๐ท Korea: New 4 Major Insurance rates & Minimum Wage effective Jan 1 | src/rules/2026/jp.mjs, src/rules/2026/kr.mjs |
| 3ๆ (Q1) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: Kyokai Kenpo prefectural health & nursing care insurance rate revision / ๐ฐ๐ท Korea: Revised Wage Withholding Table check | src/rules/2026/jp.mjs, src/rules/2026/kr.mjs |
| 4ๆ (Q2) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: New fiscal year (April) Employment Insurance rate, National Pension premium & Lump-Sum Withdrawal table update | src/rules/2026/jp.mjs |
| 6ๆ (Q2) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: New Resident Tax (ไฝๆฐ็จ) special collection cycle begins in June โ verify basic deductions & exemptions | src/rules/2026/jp.mjs |
| 9ๆ (Q3) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: NTA publishes next yearโs Withholding Tax Table in Sept & Employeesโ Pension standard remuneration update | src/rules/2026/jp.mjs |
| 10ๆ (Q4) | ๐ฏ๐ต JP | ๐ฏ๐ต Japan: Regional minimum wage revisions take effect (Oct) & Year-End Tax Adjustment (ๅนดๆซ่ชฟๆด) form updates | src/rules/2026/jp.mjs |
๐๏ธ ๐ฏ๐ต ์ผ๋ณธ (Japan) โ ์ ๋ถ ๊ณต์ ๊ธฐ๊ด 1์ฐจ ์๋ฃ ์ถ์ฒ
| ๊ตญ๊ฐ | ๊ณต์ ๊ธฐ๊ด๋ช | ๊ณต์ ์ธ์จยท์์จ ์๋ฌธ ๋งํฌ | ์ ๊ธฐ ์ ๊ฒ ์ฃผ๊ธฐ | ์ต๊ทผ ๊ฒ์ฆ์ผ |
|---|---|---|---|---|
| ๐ฏ๐ต JP | National Tax Agency of Japan (ๅฝ็จๅบ) | 2026/2027 Withholding Tax Tables & Computer Formula (ๆบๆณๅพดๅ็จ้ก่กจ) | ๋งค๋ 9์ ์ฐจ๋ ๋ ํ ๊ณต๊ฐ โ 1์ ๊ธ์ฌ๋ถํฐ ์ ์ฉ (1์ยท9์ ์ค์ ์ ๊ฒ) | 2026-11-04 |
| ๐ฏ๐ต JP | Japan Health Insurance Association (ๅไผใใใฝ) | Prefectural Health & Nursing Care Insurance Rate Tables | ๋งค๋ 3์๋ถ(4์ ๋ฉ๋ถ๋ถ)๋ถํฐ ๋๋๋ถํ๋ณ ์์จ ๊ฐ์ (2์ยท3์ยท4์ ์ค์ ์ ๊ฒ) | 2026-11-04 |
| ๐ฏ๐ต JP | Japan Pension Service (ๆฅๆฌๅนด้ๆฉๆง) | Employeesโ Pension Rates & Lump-Sum Withdrawal Payments (่ฑ้ไธๆ้) | ๊ตญ๋ฏผ์ฐ๊ธ ๋ณดํ๋ฃ ๋งค๋ 4์ ๊ฐ์ / ํ์์ฐ๊ธ ์ ๊ธฐ๊ฒฐ์ 9์ (3์ยท4์ยท9์ ์ ๊ฒ) | 2026-11-04 |
| ๐ฏ๐ต JP | Ministry of Health, Labour and Welfare (ๅ็ๅดๅ็) | Employment Insurance Rates, Regional Minimum Wage & Income Wall Package | ๊ณ ์ฉ๋ณดํ ๋งค๋ 4์ / ์ง์ญ๋ณ ์ต์ ์๊ธ ๋งค๋ 10์ ๋ฐํจ (3์ยท4์ยท9์ยท10์ ์ ๊ฒ) | 2026-11-04 |
| ๐ฏ๐ต JP | Ministry of Internal Affairs and Communications (็ทๅ็) | Individual Resident Tax (ไฝๆฐ็จ) & Forest Environment Tax System | ๋งค๋ 6์ ์ ๊ท ์ฐ๋ ์ฃผ๋ฏผ์ธ ๋ถ๊ณผ ์์ (5์ยท6์ ์ค์ ์ ๊ฒ) | 2026-11-04 |
| ๐ฏ๐ต JP | Immigration Services Agency of Japan (ๅบๅ ฅๅฝๅจ็็ฎก็ๅบ) | Permission to Engage in Activity Other Than That Permitted (28h/week Rule) | ๋ถ๊ธฐ๋ณ ์ถ์ ๊ตญ๊ด๋ฆฌ๋ฒ ์ํ๊ท์น ๊ฐ์ ์ฌ๋ถ ์ ๊ฒ (1ยท4ยท7ยท10์) | 2026-11-04 |
๐ Monthly & Quarterly Verification Workflow
- 1. Automated Radar Check: Run `npm run check-updates` to check which Japanese and Korean agencies have scheduled revisions this month/quarter and verify live connectivity to official government URLs.
- 2. Primary Source Audit: Cross-check figures against the official links below (Japan NTA, Kyokai Kenpo, Japan Pension Service, Korea NTS, and 4 Major Insurance Portal).
- 3. Single-Source Rule Update: Updating `src/rules/2026/jp.mjs` or `kr.mjs` and running `npm run build` automatically updates every calculator across all 5 languages plus `/llms-full.txt` and `/api/rules-2026.json`.