What’s Changing on September 24, 2026
The National Tax Agency (国税庁) is rolling out a major system overhaul (国税システムの更改) on 令和8年9月24日, affecting:
- All paper forms:申告書 (tax return), various applications, notifications. (nta.go.jp)
- Legal schedule forms (法定調書): same.
- Income tax collection statement (所得税徴収高計算書): the field “整理番号” (8 digits) changes to “お問い合わせ番号” (13 digits). (nta.go.jp)
Also:
- Claiming returns or documents on paper will require the updated forms once they are published.
- Use of colour forms will largely end; priority on black-and-white printing. (nta.go.jp)
What Entities and Individuals Must Do Now
- Tax professionals and corporate bookkeeping teams: ensure that your software or e-Tax service providers are updated by early September. vendor software must support new layouts and field changes. (nta.go.jp)
- Employers and payroll departments: review withholding and reporting templates, especially the new “問い合わせ番号”.
- Taxpayers using paper forms: when the updated forms go live, switch immediately — otherwise your filings may be rejected for using outdated versions.
Impact on e-Tax, IP, and Notifications
- IP address changes: fixed IP addresses formerly used to connect to e-Tax will be replaced by dynamic IP post-September 24. If you use static-IP setups, confirm you can transition. (nta.go.jp)
- Electronic delivery of notices: the method for consent is also changing. Default may shift to a one-time bulk consent rather than case-by-case. (nta.go.jp)
Compliance Tips & Best Practices
- Subscribe to NTA’s information page to receive updated form PDFs. Forms guide and PDF releases will detail which forms are changed.
- If you outsource payroll or tax preparation, ensure your external vendor is aware and testing with the new format now.
- Conduct internal form audits before submissions: compare old vs. new layouts to identify missing fields.
Why This Matters
Failing to use correct forms or outdated models can lead to:
- Rejection of submissions or delays in processing.
- Misreporting, especially with number fields, causing computation or audit issues.
- Discrepancies with withholding, possibly resulting in over-or undercollected tax.
With only a short lead time before the September switch-over, early preparation is essential to remain compliant and avoid costly corrections.