Home-office expenses
Rent, utilities, internet, phone, allocation methods, and evidence.
If you work from home, you can deduct only the business portion of rent, utilities, internet, and phone, using a defensible allocation such as floor area or working time — “I work from home” does not justify deducting 100% of your housing.
Effective: 2026-01-01 to 2026-12-31
Professional review pending — treat as draft and confirm with the authorities.
Key points
- Only the business portion is deductible (家事按分).
- Use a defensible method: floor area, dedicated room, working time, or data usage.
- Keep the calculation and update it when arrangements change.
- 100% of rent/utilities is not deductible just because you work from home.
Allocating fairly
The rule is that mixed expenses are deductible for the portion objectively used for business. A common method for rent and utilities is floor area (the share of your home used only for work), and for internet and phone, working time or data usage. Whatever basis you pick, document it and apply it consistently; a dedicated workroom makes the allocation easier to defend.
Evidence and risk
Keep the floor-area calculation, a note of your method, and the underlying bills. Over-allocating housing and utilities is a frequent audit adjustment, so be conservative and realistic. Update the calculation if you move, change rooms, or shift how much you work from home during the year.
Who this is for
- Home-based freelancers
- Anyone deducting mixed expenses
What this is not
- Employees (limited expense rules)
- Over-claiming home expenses is a common audit adjustment; keep the calculation conservative and documented.
Frequently asked questions
Do I need to file a tax return in Japan?
Many employees do not, because tax is settled by year-end adjustment (年末調整). You generally must file (確定申告) if you have side income over ¥200,000, two or more employers, self-employment income, sizeable investment or crypto gains, or you want to claim deductions like large medical costs or a first-year mortgage credit. Filing season is Feb 16 – Mar 15 via e-Tax. When unsure, check the NTA guidance or ask a 税理士.