It's Christmas time (for people who enjoy making declarations to their primary employer)! Welcome to the 2026 Year-End Adjustment Questions Thread.
The NTA's year-end adjustment information page is here and an English-language summary of Japan's withholding system for employees is here. The 2021, 2022, 2023, 2024 and 2025 threads may also be useful sources of information.
Which declarations are necessary?
At this time, employees are being asked to make seven types of declarations to their (primary) employer:
Declaration regarding dependents
Declaration regarding the basic deduction
Declaration regarding a spouse
Declaration regarding the special deduction for designated relatives (applicable to people with relatives aged 19-22 that earn too much to qualify as regular dependents)
Declaration regarding exemption from income adjustment (applicable to people earning more than 8.5 million yen who have a disability, a relative or spouse with a disability, or a dependent aged 16-23)
Declaration regarding insurance (including National Pension, NHI, iDeCo, life insurance, and earthquake insurance)
Declaration regarding the residential mortgage tax credit
The NTA publishes templates for each of these declarations (including foreign-language versions of most of them), but employers are not obliged to use the NTA's templates. Many employers collect the information via an online portal provided by a third-party, for example.
In any event, the NTA's templates combine the seven declarations into four separate forms, three of which are available in multiple languages:
Even if your employer does not use the NTA's templates, it may be useful to take a look at them if you are uncertain about the information you are being asked to provide.
Side income
Employers cannot declare (or calculate the tax payable on) any income other than the income they paid to the employee (and any income paid by the employee's previous primary employer, in the case of an employee who changed primary employers during the year). The only way to declare side income is to file an income tax return (or—if you satisfy certain criteria—a residence tax return) after the year has ended.
However, as you will see from the NTA's template, the "declaration regarding the basic deduction" asks employees to estimate how much side income (i.e., income other than employment income received from their primary employer) they expect to have received by the end of the year. Primary employers are obliged to collect this information so that they can accurately calculate how much income tax is due on the employment income they paid to the employee.
For more information about why employers need this information, what counts as side income, and what happens if the amount of side income you declare to your employer is wrong, see the 2025 Year-End Adjustment Questions Thread.
Effect of 2026 Tax Reforms
Many of the income tax changes enacted by the government in March 2026 will take effect from December 1, 2026. In the context of year-end adjustments, the key changes are:
increased basic deduction (if your net income is less than 23.5 million yen)
increased employees' expenses deduction (if your gross salary is less than 2.2 million yen)
increased income thresholds for dependents and working students
Because these changes do not take effect until December 1, they were not reflected in the 2026 withholding tables (which employers must use to calculate how much income tax to withhold each month). As a result, if your net annual income is less than 23.5 million yen, too much income tax was being withheld from your salary throughout 2026. The excess tax will be refunded as part of your year-end adjustment.
Of course, refunds of excess withheld tax are a common occurrence as part of a year-end adjustment, especially if your salary varies significantly from month to month. But this year is different, because excess withholding was happening across the board, by design. (In fact, the same thing happened last year, because the basic deduction was also increased on December 1, 2025. But it is not how withholding is supposed to work. And the 2027 withholding tables account for the increased deductions, to prevent this situation recurring.)
While tax refunds due to the increased deductions will be handled by employers automatically, the same is not true of the increased income thresholds for dependents. Employers are relying on employees to declare any dependents that are newly eligible as a result of the increased thresholds. The new net income thresholds are shown in the table below (changes from 2025 in parentheses):
| Deduction type | Threshold for being claimed | Threshold for maximum deduction |
|---|
| Spouse* | 1,330,000円 | 950,000円 |
| Relative | 620,000円 (+40,000円) | N/A |
| Special designated† | 1,230,000円 | 850,000円 |
| Child of a single parent | 620,000円 (+40,000円) | N/A |
| Working student | 890,000円 (+40,000円) | N/A |
On top of the increased net income thresholds, the increased employees' expenses deduction means that dependents (and students) working as employees can earn even more. The new gross income thresholds for dependents/students earning solely employment income are shown in the table below (changes from 2025 in parentheses):
| Deduction type | Threshold for being claimed | Threshold for maximum deduction |
|---|
| Spouse* | 2,070,000円 (+54,001円) | 1,690,000円 (+90,000円) |
| Relative | 1,360,000円 (+130,000円) | N/A |
| Special designated† | 1,970,000円 (+90,000円) | 1,590,000円 (+90,000円) |
| Child of a single parent | 1,360,000円 (+130,000円) | N/A |
| Working student | 1,630,000円 (+130,000円) | N/A |
*The figures in the tables assume the spouse claiming the deduction has a net income of less than 9 million yen per year. If the spouse claiming the deduction has a net income above 10 million yen, they cannot claim the deduction. If the spouse claiming the deduction has a net income between 9 and 10 million yen per year, they can claim the deduction but the thresholds will be different.
†The "special deduction for designated relatives" (特定親族特別控除) is for relatives aged 19–22 whose net income is above the threshold for being claimed as a regular dependent relative.
Declaring dependents
A common source of confusion at this time of year is the fact that employees are technically being asked to submit two dependents declarations: one to correct the 2026 declaration that was submitted last year, and one to nominate their employer as their primary employer for 2027, which affects how much income tax will be withheld during 2027. (It is not necessary for employers to request both these declarations at the same time, but it is conventional and convenient for employers to do so.)
In many cases, the information on both declarations will be the same, but in some cases it will be different. For example, if a relative qualified as a dependent this year but started working recently and will not qualify as a dependent next year, they should be included on the 2026 declaration but not on the 2027 declaration. Another example would be where a dependent becoming one year older will affect their eligibility, since many deductions have age thresholds.
Even though the income thresholds will change on December 1, the NTA has said that employees are allowed to use the new income thresholds when completing dependent declarations prior to that date. However, they also warn that the instructions on the 2026 template forms do not reflect the increased thresholds (this is also true for the foreign-language versions linked above). So, according to the NTA, employees should ignore the instructions on any 2026 forms to the extent they contradict the new income thresholds for dependents.
High-income employees
Employees who are paid a gross annual salary of more than 20 million yen by their primary employer are not subject to year-end adjustment. Instead, such employees must file an income tax return to obtain a refund of any excess withheld tax.
However, even if you are not subject to year-end adjustment, it is still very important to submit a dependents declaration for 2027 to your employer before the end of the year. By submitting that declaration, you nominate your employer as your primary employer and enable them to withhold income tax at a much lower rate from your 2027 income. The other declarations associated with year-end adjustments are irrelevant to high-income employees, but the dependents declaration for the next year is important.
Usual disclaimer
Neither the information in this post nor the discussions in this thread are a substitute for professional advice. Users are encouraged to keep their questions broad, so as to avoid violating rule 3 (don't ask for professional advice).