Compliance
Navigating Japan’s Tax System Update: e-Tax Redesign & What Expatriates Must Know
A major overhaul of Japan’s national tax system is on the horizon. Learn how the changes to e-Tax, form formats, and filing procedures could affect expats and international residents.
By NomadicTax Research Team • 5-8 min read • September 10, 2026
## What’s Changing in the Tax System Redesign
Japan’s **National Tax Agency (NTA)** is implementing a sweeping **system upgrade scheduled for September 24, 2026**. These changes will touch several areas of tax compliance and administration.([nta.go.jp](https://www.nta.go.jp/taxes/shiraberu/sodan/system.htm?utm_source=openai))
### Key updates:
- **Forms and format changes**: Paper-based declarations, applications, notifications, and statutory reports will be redesigned. Notably, the longstanding "整理番号" (8-digit reference number) will be replaced with a new **13-digit "お問い合わせ番号"** (Inquiry Number).([nta.go.jp](https://www.nta.go.jp/taxes/shiraberu/sodan/system.htm?utm_source=openai))
- **Color scheme and layout**: Forms will shift to simpler, primarily black-and-white designs. Some controls and data fields will be restructured.([nta.go.jp](https://www.nta.go.jp/taxes/shiraberu/sodan/system.htm?utm_source=openai))
- **e-Tax platform updates**: After the system update on **September 24**, e-Tax will see changes in IP address behavior (moving to dynamic IPs), as well as alterations to electronic delivery procedures for tax notices.([nta.go.jp](https://www.nta.go.jp/taxes/shiraberu/sodan/system.htm?utm_source=openai))
## What Expats Should Be Aware Of
These changes could especially affect international residents and foreign-source income filers:
| Area | Why It Matters |
|---|---|
| **Statutory documents** (e.g. withholding slips, income certificates) | These may require updated formats, particularly as legal forms (法定調書) change. Foresee revisions to standard forms used in employment or investment income reporting.([nta.go.jp](https://www.nta.go.jp/law/tsutatsu/kobetsu/hotei/kaisei/260630/index.htm?utm_source=openai))|
| **Filing via software or third party providers** | Vendors will need to update their outputs to match redesigned forms and specifications. Verify that your software shows the Inquiry Number field and supports the new form styles.([e-tax.nta.go.jp](https://www.e-tax.nta.go.jp/shiyo/ksk2/ksk2_shiyo.htm?utm_source=openai))|
| **Deadlines around system maintenance** | e-Tax access will be severely limited during maintenance windows (e.g. September 19-24, and Sept 26, 2026). Plan ahead so filings that are time-sensitive are submitted outside these windows.([e-tax.nta.go.jp](https://www.e-tax.nta.go.jp/topics/2026/topics_20260422.htm?utm_source=openai))|
## Practical Steps to Stay Compliant
1. **Audit your records and templates**: If you prepare financials or tax filings, check current forms and note where the Inquiry Number wasn’t used previously, or where color formatting was present.
2. **Coordinate with your employer or tax preparer**: To ensure the forms you receive (e.g. for payroll, pension, dividends) are in the new format when required.
3. **Backup filings**: If deadlines coincide with e-Tax downtime, consider paper submissions where allowed. When submitting electronically, retain confirmation of transmission when allowable.
4. **Monitor vendor updates**: If you use accounting or tax software, request documentation or assurance that the vendor supports the revised forms and e-Tax system changes.
## Example
Suppose you have investment income from a foreign stock and receive a withholding slip in October 2026. Under the new requirements, that slip—since it’s a statutory document—will need the Inquiry Number printed. If the slip still uses the old format or reference fields, you should request the updated form from issuer or employer to ensure compliance.
## Bottom Line
While the changes are technical, their ramifications are broad—especially for those with international income or who rely on traditional form-driven filings. Staying ahead of the redesign will save you headaches come tax season.