2026 Tax Filing: e-Tax Home Filing Guide — File Your Japanese Taxes from Home with My Number Card + Smartphone

Disclaimer: This article provides general information only and does not constitute tax or legal advice. Please consult a qualified tax professional (zeirishi) for advice specific to your situation. Information is based on official National Tax Agency (NTA) sources and current as of January 2026.Disclosure: This article is published by Denpyo, a receipt and expense management service. Some tools and services mentioned include Denpyo products.

Introduction: The Era of "Paperless Tax Filing"

"Tax filing is such a hassle..." "I don't have time to go to the tax office..." "I don't understand Japanese tax forms..."

If you're a foreigner living in Japan, these concerns are completely understandable. The good news? e-Tax (Japan's electronic tax filing system) solves all of these problems.

Starting with the 2026 tax filing season, if you have a My Number Card (mainambaa kaado) and a smartphone, you can file your tax return from home 24 hours a day. Better yet, with My Number Portal integration (maina pootaru renkei), your salary information, furusato nozei donations, and medical expenses are automatically entered — making truly "paperless tax filing" a reality.

What you'll learn in this article:

• 5 key benefits of using e-Tax

• Information automatically imported via My Number Portal

• How to authenticate with your smartphone

• Step-by-step e-Tax filing process

• What to do if you encounter problems

1. What is e-Tax? 5 Key Benefits

e-Tax (National Tax Electronic Filing and Payment System) is an online tax filing system provided by Japan's National Tax Agency (NTA). The name comes from "electronic Tax."

Benefit 1: File from Home 24 Hours a Day

No need to worry about tax office hours or waiting in long lines. You can file anytime — late at night or early morning — as long as you have an internet connection.

2026 Tax Filing Period: February 16 (Mon) - March 16 (Mon)

Refund claims (kanpu shinkoku — when you're getting money back) are accepted starting January 1, giving you a head start.

Benefit 2: No Need to Submit Attached Documents

Traditional paper filing required attaching physical copies of withholding slips (gensen choushuu-hyou) and deduction certificates. With e-Tax, you can skip submitting many of these documents.

Important: You must still keep these documents for 5 years in case of audit.

Benefit 3: Auto-Input via My Number Portal Integration

This is e-Tax's biggest advantage. By connecting with My Number Portal (Maina Pootaru), the following information is automatically entered into your tax return:

Before My Number Portal: Manual data entry, keeping stacks of paper, tedious calculations

After My Number Portal: Automatic data import, no paper management, scan results directly entered into your return

Source: NTA My Number Portal Integration

Benefit 4: Faster Tax Refunds

Filing via e-Tax significantly speeds up refund processing:

If you're expecting a refund, e-Tax gets your money back faster.

Benefit 5: Required for Maximum Blue Form Deduction

If you're a freelancer or sole proprietor using Blue Form filing (aoiro shinkoku), e-Tax electronic filing is mandatory to receive the maximum special deduction of 650,000 yen. Paper submission reduces this to 550,000 yen.

This requirement has been in place since the 2020 tax year.

2. What You Need for e-Tax

2.1 Required Items

Essential:

• My Number Card — Your electronic certificate must be valid (not expired)

• Smartphone — A model compatible with My Number Card reading (NFC-enabled)

Alternative Setup:

• Computer + IC Card Reader/Writer

New for 2026: Starting with 2026 (Reiwa 7) tax filing, you can submit tax returns via e-Tax without scanning your My Number Card with a smartphone (currently iPhone only). This makes the process even more convenient.

2.2 Compatible Smartphone Models

How to check compatibility: Install the My Number Portal app and test if it can successfully read your My Number Card.

2.3 Advance Preparation

1. Get a My Number Card — If you don't have one, apply at your municipal office (shiyakusho/kuyakusho). Processing typically takes 1-2 months.

1. Verify your electronic certificate — Check the expiration date (valid for 5 years from issuance). If expired, renew at your municipal office.

1. Confirm your PIN codes — You'll need two PINs: User authentication certificate PIN (4 digits) Signature certificate PIN (6-16 characters) Forgot your PINs? Reset them at your municipal office.

1. Install the My Number Portal app — Available on both iOS and Android app stores.

3. Benefits of My Number Portal Integration

3.1 What Gets Auto-Imported

With My Number Portal integration, the following information is automatically entered into your tax return:

For Salary Earners:

• Salary income withholding slip data (gensen choushuu-hyou)

• Retirement income withholding slip data

• Public pension withholding slip data

Deduction-Related:

• Furusato Nozei donation certificates (kifu-kin koujo)

• Life insurance premium deduction certificates (seimei hoken-ryou koujo)

• Earthquake insurance premium deduction certificates

• Medical expense notification information (iryouhi tsuuchi)

• Housing loan deduction documents (juutaku loan koujo)

Source: NTA My Number Portal Integration Guide

3.2 Who Benefits Most

My Number Portal integration is especially convenient for:

• Salary earners — Your employer's data flows directly into your return

• Those claiming multiple deductions — No more manual entry for each one

• Furusato nozei donors to multiple municipalities — All donations auto-imported

• Those with significant medical expenses — Health insurance data automatically included

4. Smartphone Authentication Methods

4.1 Traditional Method

Previously, e-Tax authentication required:

• My Number Card (physical card)

• IC card reader or smartphone

• Scanning your card each time you log in

4.2 New Authentication Method (From 2026)

Your User ID and password can now use your smartphone's biometric authentication! (Availability varies by device)

This means hassle-free authentication once you've completed initial setup.

Important: Initial authentication still requires your My Number Card. After that, subsequent logins can use biometrics — no card needed.

5. e-Tax Filing Steps [Step-by-Step]

Step 1: Preparation

1. Prepare your My Number Card — Keep it handy for authentication

1. Install the My Number Portal app — Download from your app store

1. Confirm your PIN codes — If forgotten, reset at your municipal office before the filing deadline

Step 2: Set Up My Number Portal Integration

1. Log in to My Number Portal — Use your smartphone to scan your My Number Card

1. Configure "Private Delivery Service" — This enables various certificate providers to send data

1. Link external services — Connect your insurance companies, furusato nozei portals, etc.

Pro tip: Set this up well before tax season. Some services take several days to establish the connection.

Step 3: Create Your Tax Return

1. Access the NTA "Tax Return Preparation Corner" (Kakutei Shinkokusho-tou Sakusei Koonaa) at https://www.keisan.nta.go.jp/

1. Click "Start Preparation" — The site is available in Japanese only, but modern browsers can translate

1. Select your filing type — Income tax (shotoku-zei), consumption tax, etc.

1. Import data via My Number Portal — Click the option to retrieve linked data

1. Review and edit auto-entered content — Verify everything looks correct

1. Enter additional information — Business expenses, other deductions not auto-imported

Step 4: Submit Your Return

1. Final review — Double-check all amounts and information

1. Electronic signature — Authenticate with your My Number Card

1. Submit via e-Tax — Send your completed return electronically

1. Save your confirmation — Download or screenshot the submission receipt for your records

Source: NTA Tax Return Preparation Corner

6. If You Have Trouble Filing

6.1 Video Guides

The NTA provides video tutorials (in Japanese) for using the Tax Return Preparation Corner. These visual guides can be helpful even if you don't understand all the spoken Japanese.

NTA YouTube Channel

6.2 Chatbot "Futaba"

Enter your question or select from the menu, and AI will automatically respond. While the chatbot operates in Japanese, it can help with basic navigation questions.

Available: 24 hours a day

6.3 Consult Your Tax Office

For complex cases or questions you can't resolve online, you can consult your local tax office (zeimusho). Many tax offices have English-speaking staff or can arrange interpretation services during peak filing season.

Tip: Call ahead to ask about English support availability.

7. Especially Recommended for Salary Earners

Employees, part-timers, and temporary workers (kyuuyo shotokusha / salary earners) benefit most from e-Tax and My Number Portal integration.

Why?

1. Withholding slip auto-entered — Your company's payroll data flows directly into your return with no manual entry

1. File additional deductions easily — Claim deductions not covered by year-end adjustment (nenmatsu chousei), such as medical expense deductions or furusato nozei

1. Faster refunds — Receive your refund in about 3 weeks

When Do Salary Earners Need to File?

8. Frequently Asked Questions (FAQ)

Q1: Is a My Number Card required to use e-Tax?

A: Recommended but not strictly required. You can file using the "ID/Password method" (ID pasuwado houshiki) instead. However, the My Number Card method is required for My Number Portal integration and biometric authentication features.

To use the ID/Password method, you must first register in person at a tax office.

Q2: Can I file taxes using only a smartphone?

A: Yes, you can. The "Tax Return Preparation Corner" is fully smartphone-compatible. You can complete the entire process — from data entry to My Number Card scanning to submission — on your phone.

Tip: A larger screen (tablet or computer) may be more comfortable for reviewing detailed tax information.

Q3: Do I need an IC card reader?

A: Not if you use a smartphone for reading your My Number Card. An IC card reader is only needed if you want to use a computer without smartphone assistance.

Q4: What gets auto-filled with My Number Portal integration?

A: Withholding slips, furusato nozei donation certificates, medical expense notifications, life insurance deduction certificates, housing loan deduction documents, and more. Coverage is expanding each year.

Note: Not all employers and institutions participate yet. Check whether your specific data sources are available through My Number Portal.

Q5: What are e-Tax's operating hours?

A: During the tax filing period (February 16 - March 16), e-Tax is available 24 hours a day, 7 days a week. Outside this period, there are occasional maintenance windows — typically late at night.

Q6: Is my filing data secure?

A: Yes. e-Tax uses encrypted communication (SSL/TLS), and data is transmitted securely. My Number Card verification with PIN codes prevents unauthorized access. Your tax data is protected by the same security standards used for other government systems.

Q7: What if I make a mistake on my e-Tax filing?

A: You can file an amended return (shuusei shinkoku) if you need to correct errors. If the correction results in additional tax owed, file promptly to minimize penalty charges.

Summary

2026 tax filing becomes surprisingly easy with e-Tax and My Number Portal integration.

Key Points:

1. File from home 24 hours a day — No need to visit the tax office or wait in line

1. Auto-entry via My Number Portal — Salary, furusato nozei, and medical expenses auto-filled

1. Easy login with smartphone biometrics — Reduced card scanning hassle after initial setup

1. Faster refunds — Receive your refund in about 3 weeks vs. 1-2 months for paper

1. Required for maximum Blue Form deduction — Freelancers need e-Tax for the full 650,000 yen deduction

2026 Filing Deadline: March 16 (Monday)

Don't wait until the last minute — start gathering your documents and setting up My Number Portal integration now.

Useful Links

• Tax Return Preparation Corner — NTA's official e-Tax filing portal

• My Number Portal — Manage your My Number Card and linked services

• Start Expense Management with Denpyo — Track receipts and expenses for tax filing

Key Japanese Terms Glossary