๐Ÿ“… 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.

๐Ÿ—“๏ธ 1์›” ~ 12์›” ์—ฐ๊ฐ„ ์„ธ๊ธˆยท์‹ ๊ณ ยทํ™˜๊ธ‰ ์ผ์ • ํ•œ๋ˆˆ์— ๋ณด๊ธฐ (Annual Tax & Filing Calendar)

๐Ÿ“… 1์›” (1ๆœˆ) ์ผ์ • 3๊ฑด

๐Ÿ“Œ 1/1 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Resident Tax Assessment Date (Jan 1) & New Withholding Table

Having a registered address in Japan on Jan 1 triggers Resident Tax billing starting in June.

๐Ÿ“Œ 1/15~2/15 KR
๐Ÿ‡ฐ๐Ÿ‡ท Korea Year-End Tax Settlement (Hometax Portal Opens)

Download deduction records from NTS Hometax and submit to your employer.

๐Ÿ“Œ 1/31 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Resident Tax (Ordinary Collection Q4) Payment Deadline

Final quarterly installment deadline for residents paying via city hall slips.

๐Ÿ“… 2์›” (2ๆœˆ) ์ผ์ • 2๊ฑด

๐Ÿ“Œ 2/16~3/15 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Final Tax Return (็ขบๅฎš็”ณๅ‘Š) Filing Season Opens

Reclaim overpaid Column B (ไน™ๆฌ„) tax, medical deductions, or dividend tax credits via e-Tax.

๐Ÿ“Œ 2์›” ๊ธ‰์—ฌ์ผ KR
๐Ÿ‡ฐ๐Ÿ‡ท Korea Year-End Tax Settlement Refund Paid in Feb Payroll

Your Korean year-end tax adjustment refund or balance is settled in February payroll.

๐Ÿ“… 3์›” (3ๆœˆ) ์ผ์ • 2๊ฑด

๐Ÿ“Œ 3/1~ JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Kyokai Kenpo Health & Nursing Care Insurance Rate Revision

Updated prefectural health insurance rates take effect from March coverage (April paycheck).

๐Ÿ“Œ 3/15 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Income Tax Final Return (็ขบๅฎš็”ณๅ‘Š) Deadline (Mar 15)

Mandatory filing and payment deadline if you owe tax (refund-only claims can be filed for 5 years).

๐Ÿ“… 4์›” (4ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 4์›”~6์›” ๊ธ‰์—ฌ JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Aprโ€“Jun Pay Determines Full-Year Social Insurance Bracket

Overtime worked paid in Apr, May, and Jun raises your health and pension bracket from September.

๐Ÿ“… 5์›” (5ๆœˆ) ์ผ์ • 2๊ฑด

๐Ÿ“Œ 5/1~5/31 KR
๐Ÿ‡ฐ๐Ÿ‡ท Korea May Comprehensive Income Tax Filing & 3.3% Freelance Refund Month

File on NTS Hometax between May 1โ€“31 to reclaim 3.3% freelance withholding or report combined dividend income >โ‚ฉ20M.

๐Ÿ“Œ 5์›” ์ค‘์ˆœ~๋ง JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Resident Tax Assessment Notice Distributed & Auto Tax Due (May 31)

Check your Resident Tax notice to verify dependent deductions and Furusato Nozei credits.

๐Ÿ“… 6์›” (6ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 6์›” ๊ธ‰์—ฌ & 6/30 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan New Resident Tax Cycle Starts (June Paycheck) & Q1 Slip Deadline (Jun 30)

Second-year residents see Resident Tax deducted for the first time on their June payslip.

๐Ÿ“… 7์›” (7ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 7/1 KR
๐Ÿ‡ฐ๐Ÿ‡ท Korea National Pension Monthly Income Cap & Floor Adjustment (Jul 1)

Annual revision of the Korean National Pension contribution ceiling takes effect every July.

๐Ÿ“… 8์›” (8ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 8/31 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Resident Tax (Ordinary Collection Q2) Payment Deadline (Aug 31)

Second quarterly installment deadline for Ordinary Collection Resident Tax.

๐Ÿ“… 9์›” (9ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 9์›” ๊ธ‰์—ฌ~ JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan New Social Insurance Brackets Applied (from Aprโ€“Jun Pay) & Next Year Tax Table

Your updated Health Insurance and Welfare Pension deductions take effect starting with September coverage.

๐Ÿ“… 10์›” (10ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 10/1 & 10/31 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Regional Minimum Wage Hike Takes Effect (Oct) & Resident Tax Q3 Due (Oct 31)

Prefectural minimum wages increase in October, and Year-End Tax insurance certificates begin arriving by mail.

๐Ÿ“… 11์›” (11ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 11์›” ์ „์ฒด JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Company Year-End Tax Adjustment (ๅนดๆœซ่ชฟๆ•ด) Form Submission Month

Submit your 3 Year-End Tax Adjustment forms and overseas dependent remittance proofs to HR.

๐Ÿ“… 12์›” (12ๆœˆ) ์ผ์ • 1๊ฑด

๐Ÿ“Œ 12์›” ๊ธ‰์—ฌ & 12/31 JP
๐Ÿ‡ฏ๐Ÿ‡ต Japan Dec Paycheck Tax Refund (ๅนดๆœซ่ชฟๆ•ด้‚„ไป˜) & Dec 31 Furusato Nozei / Moving-Out Cutoff

Year-end tax refunds arrive in Dec payroll. Leaving Japan before Dec 31 avoids next yearโ€™s Resident Tax.

๐Ÿ“† ์›”๋ณ„ยท๋ถ„๊ธฐ๋ณ„ ์„ธ๋ฒ•ยท๋ณดํ—˜๋ฃŒ์œจ ์ •๊ธฐ ์ ๊ฒ€ ๋‹ฌ๋ ฅ (Monthly & Quarterly Revision Schedule)

์›” / ๋ถ„๊ธฐ ๋Œ€์ƒ ๊ตญ๊ฐ€ ์ ๊ฒ€ ๋ฐ ๊ฐœ์ • ๋ฐ˜์˜ ํ•ญ๋ชฉ ๊ทœ์น™ ํŒŒ์ผ ์œ„์น˜
1ๆœˆ (Q1) JP ยท KR ๐Ÿ‡ฏ๐Ÿ‡ต Japan: New year Withholding Tax Table takes effect / ๐Ÿ‡ฐ๐Ÿ‡ท Korea: New 4 Major Insurance rates & Minimum Wage effective Jan 1 src/rules/2026/jp.mjs, src/rules/2026/kr.mjs
3ๆœˆ (Q1) JP ยท KR ๐Ÿ‡ฏ๐Ÿ‡ต Japan: Kyokai Kenpo prefectural health & nursing care insurance rate revision / ๐Ÿ‡ฐ๐Ÿ‡ท Korea: Revised Wage Withholding Table check src/rules/2026/jp.mjs, src/rules/2026/kr.mjs
4ๆœˆ (Q2) JP ๐Ÿ‡ฏ๐Ÿ‡ต Japan: New fiscal year (April) Employment Insurance rate, National Pension premium & Lump-Sum Withdrawal table update src/rules/2026/jp.mjs
5ๆœˆ (Q2) KR ๐Ÿ‡ฐ๐Ÿ‡ท Korea: May Comprehensive Income Tax filing season โ€” check 3.3% freelancer expense rates & financial income rules src/rules/2026/kr.mjs
6ๆœˆ (Q2) JP ๐Ÿ‡ฏ๐Ÿ‡ต Japan: New Resident Tax (ไฝๆฐ‘็จŽ) special collection cycle begins in June โ€” verify basic deductions & exemptions src/rules/2026/jp.mjs
7ๆœˆ (Q3) KR ๐Ÿ‡ฐ๐Ÿ‡ท Korea: National Pension monthly income cap & floor annual adjustment (effective July 1) src/rules/2026/kr.mjs
9ๆœˆ (Q3) JP ๐Ÿ‡ฏ๐Ÿ‡ต Japan: NTA publishes next yearโ€™s Withholding Tax Table in Sept & Employeesโ€™ Pension standard remuneration update src/rules/2026/jp.mjs
10ๆœˆ (Q4) JP ๐Ÿ‡ฏ๐Ÿ‡ต Japan: Regional minimum wage revisions take effect (Oct) & Year-End Tax Adjustment (ๅนดๆœซ่ชฟๆ•ด) form updates src/rules/2026/jp.mjs

๐Ÿ›๏ธ ๊ณต์‹ ๋ ฅ ์žˆ๋Š” ํ•œยท์ผ ์ •๋ถ€ ๊ณต์‹ ๊ธฐ๊ด€ 1์ฐจ ์ž๋ฃŒ ์ถœ์ฒ˜ (Primary Official Sources)

๊ตญ๊ฐ€ ๊ณต์‹ ๊ธฐ๊ด€๋ช… ๊ณต์‹ ์„ธ์œจยท์š”์œจ ์›๋ฌธ ๋งํฌ ์ •๊ธฐ ์ ๊ฒ€ ์ฃผ๊ธฐ ์ตœ๊ทผ ๊ฒ€์ฆ์ผ
๐Ÿ‡ฏ๐Ÿ‡ต JP National Tax Agency of Japan (ๅ›ฝ็จŽๅบ) 2026/2027 Withholding Tax Tables & Computer Formula (ๆบๆณ‰ๅพดๅŽ็จŽ้ก่กจ) ๋งค๋…„ 9์›” ์ฐจ๋…„๋„ ํ‘œ ๊ณต๊ฐœ โ†’ 1์›” ๊ธ‰์—ฌ๋ถ€ํ„ฐ ์ ์šฉ (1์›”ยท9์›” ์ค‘์  ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฏ๐Ÿ‡ต JP Japan Health Insurance Association (ๅ”ไผšใ‘ใ‚“ใฝ) Prefectural Health & Nursing Care Insurance Rate Tables ๋งค๋…„ 3์›”๋ถ„(4์›” ๋‚ฉ๋ถ€๋ถ„)๋ถ€ํ„ฐ ๋„๋„๋ถ€ํ˜„๋ณ„ ์š”์œจ ๊ฐœ์ • (2์›”ยท3์›”ยท4์›” ์ค‘์  ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฏ๐Ÿ‡ต JP Japan Pension Service (ๆ—ฅๆœฌๅนด้‡‘ๆฉŸๆง‹) Employeesโ€™ Pension Rates & Lump-Sum Withdrawal Payments (่„ฑ้€€ไธ€ๆ™‚้‡‘) ๊ตญ๋ฏผ์—ฐ๊ธˆ ๋ณดํ—˜๋ฃŒ ๋งค๋…„ 4์›” ๊ฐœ์ • / ํ›„์ƒ์—ฐ๊ธˆ ์ •๊ธฐ๊ฒฐ์ • 9์›” (3์›”ยท4์›”ยท9์›” ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฏ๐Ÿ‡ต JP Ministry of Health, Labour and Welfare (ๅŽš็”ŸๅŠดๅƒ็œ) Employment Insurance Rates, Regional Minimum Wage & Income Wall Package ๊ณ ์šฉ๋ณดํ—˜ ๋งค๋…„ 4์›” / ์ง€์—ญ๋ณ„ ์ตœ์ €์ž„๊ธˆ ๋งค๋…„ 10์›” ๋ฐœํšจ (3์›”ยท4์›”ยท9์›”ยท10์›” ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฏ๐Ÿ‡ต JP Ministry of Internal Affairs and Communications (็ทๅ‹™็œ) Individual Resident Tax (ไฝๆฐ‘็จŽ) & Forest Environment Tax System ๋งค๋…„ 6์›” ์‹ ๊ทœ ์—ฐ๋„ ์ฃผ๋ฏผ์„ธ ๋ถ€๊ณผ ์‹œ์ž‘ (5์›”ยท6์›” ์ค‘์  ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฏ๐Ÿ‡ต JP Immigration Services Agency of Japan (ๅ‡บๅ…ฅๅ›ฝๅœจ็•™็ฎก็†ๅบ) Permission to Engage in Activity Other Than That Permitted (28h/week Rule) ๋ถ„๊ธฐ๋ณ„ ์ถœ์ž…๊ตญ๊ด€๋ฆฌ๋ฒ• ์‹œํ–‰๊ทœ์น™ ๊ฐœ์ • ์—ฌ๋ถ€ ์ ๊ฒ€ (1ยท4ยท7ยท10์›”) 2026-11-04
๐Ÿ‡ฐ๐Ÿ‡ท KR National Tax Service of Korea (๊ตญ์„ธ์ฒญ) Wage Withholding Table, Progressive Tax Brackets, Foreigner 19% Flat Rate & Dividend Tax ๋งค๋…„ 1~2์›” ์„ธ๋ฒ• ์‹œํ–‰๋ น ๊ฐœ์ • ๋ฐ 3์›” ๊ฐ„์ด์„ธ์•กํ‘œ ๋ฐ˜์˜ / 5์›” ์ข…ํ•ฉ์†Œ๋“์„ธ (1ยท2ยท3ยท5์›” ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฐ๐Ÿ‡ท KR National Health Insurance Service (NHIS) & National Pension Service (NPS) 4 Major Social Insurance Contribution Rates & Monthly Income Caps/Floors ๊ฑด๊ฐ•ยท๊ณ ์šฉ๋ณดํ—˜ ๋งค๋…„ 1์›” / ๊ตญ๋ฏผ์—ฐ๊ธˆ ๊ธฐ์ค€์†Œ๋“์›”์•ก ์ƒยทํ•˜ํ•œ์•ก ๋งค๋…„ 7์›” ๊ฐœ์ • (1์›”ยท7์›” ์ค‘์  ์ ๊ฒ€) 2026-11-04
๐Ÿ‡ฐ๐Ÿ‡ท KR Ministry of Employment and Labor of Korea (๊ณ ์šฉ๋…ธ๋™๋ถ€) Statutory Minimum Wage, Weekly Holiday Allowance & Severance Pay Formula ์ตœ์ €์ž„๊ธˆ ๋งค๋…„ 8์›” ๊ณ ์‹œ โ†’ ์ด๋“ฌํ•ด 1์›” 1์ผ ์ ์šฉ (1์›”ยท8์›” ์ค‘์  ์ ๊ฒ€) 2026-11-04

๐Ÿ”„ 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`.