Japan · Tax basics

Japan: mileage, vehicle expenses and tax records

Necessary business expenses

How the local rules work

Necessary expenses relate to earning business income. The NTA lists business travel and other business costs; private costs need separate treatment.

What to keep

Keep receipts and records explaining each expense’s business purpose. Use journey records to help your adviser assess mixed-use vehicle costs.

What the odometer message means

The app needs total vehicle distance, including personal driving, to estimate business use. Enter beginning and ending odometer readings for the same vehicle and reporting period. Missing total distance means the percentage is incomplete; it does not erase your recorded business trips.

Example · same vehicle, same period

Business distance12,000

Total distance15,000

Business use80%

80% business · 20% personal

12,000 ÷ 15,000 × 100 = 80%. Use miles or kilometres consistently. This is a usage ratio, not automatic permission to deduct 80% of every cost.

Avoid this mistake

Do not apply a foreign standard mileage rate as a Japanese deduction. Confirm expense allocation and consumption-tax treatment separately.

Prepare your records in Free Mile Tracker

Select your country and the correct reporting period.
Review each trip and distinguish business from personal driving.
Add dated odometer readings and keep supporting expense documents.
Export your records and compare them with platform statements before filing.

A business-use percentage helps organize mixed-use records. Whether it can be used for a deduction depends on Japan’s rules and your filing method.

Official guidance

National Tax Agency: source for this guide

Source checked October 8, 2026. Confirm the applicable tax year on the official site before filing.