Medical expenses, hometown tax, insurance premiums, and other data are automatically entered. Tedious manual entry and calculation errors are eliminated. This makes filing a tax return so convenient that the impression of it being difficult is completely overturned, so make sure to enable linkage (according to the National Tax Agency). Once necessary information is entered, income, deduction amounts, and tax amounts are automatically calculated, so you don’t have to calculate them manually. The completed return can be submitted (transmitted) directly to the tax office as data. The period during which a tax return can be filed for a refund (refund return) is five years from January 1 of the year following the taxable year. Tax returns for offsetting or carrying forward investment losses, and tax returns for side job income (taxable income) must generally be filed between February 16 and March 15 of the year following the taxable year (if the first or last day falls on a Saturday or Sunday, the deadline is the following Monday) (for the 2025 tax year, the period is February 16, 2026, to March 16, 2026). Although the refund return period is generous, it’s best not to postpone and complete the procedure early. *The contents of this article are based on tax laws and regulations as of February 2026.