Home office deductions and employer-provided housing as a fringe benefit

A sole proprietor or director registered at a home address can deduct home or apartment costs in proportion to the share of floor space used for business. For owned property, only the mortgage interest is deductible (not the principal), along with depreciation calculated from the property's value, land and building tax, fire insurance, and condominium management fees — all pro-rated by ownership share and business-use share. Electricity and internet are deducted in proportion to time or floor space used for business; if a separate apartment is rented entirely as an office, the whole rent can be deducted. One accountant's rule of thumb: about 50% of utility costs can be deducted without raising questions; an unconfirmed opinion suggests up to 75% of the rent or utilities of a dedicated home office can be deducted without increasing personal taxes. Coworking rent and a portion of home rent cannot both be deducted at once — one or the other must be chosen. Separately, a company can compensate part of an employee's or director's housing rent, but the recipient must report it as additional income — simply putting the lease in the company's name without reporting the benefit is not allowed. A common scheme is "co-payment," where the company pays around 30% of the rent; opinions in the chat diverge on the exact threshold — one view holds that 70% is treated as a taxable employee benefit, another that up to 30% can be deducted without raising taxes; this discrepancy was not fully resolved. A more structured version, 役員社宅 ("director's housing"), compensates roughly 50% of rent through a corporate lease and may not directly raise the employee's taxes, unlike ordinary rent compensation — but this requires the lease itself to be held by the company, not a personal lease later reimbursed. Example calculation of the savings: company cost -5,785 yen/month, employee's net pay after rent +10,337 yen/month at a 10% resident tax rate — though the overhead of arranging a corporate lease can offset the benefit. If the lease is held by an individual rather than the company, any attempt to compensate part of it without proper structuring is classified by the NTA as a straightforwardly taxable fringe benefit.