Year-End Adjustment Guide
A complete explanation of what to submit, when, and where — plus how to fill in the declaration forms.
Dependent deduction, life insurance premium deduction, iDeCo, mortgage loan credit and more — we clearly summarize, for employees, every deduction you can claim through the year-end adjustment and how to fill in the forms.
What is the year-end adjustment?
The mechanism, why refunds happen, and why the company handles it.
BasicsTypes of declaration forms
The three declaration forms and what to write on each.
DocumentsBasic & spousal deductions
The basic deduction everyone gets, plus judging spouse/dependents.
DeductionsLife & earthquake insurance deductions
How to read the deduction certificate and calculate the amount.
DeductionsiDeCo & mortgage loan credit
Contribution deductions and claiming the mortgage credit from year two.
Tax savingDependent & single-parent deductions
Claiming when you support children, parents, or a person with a disability.
DeductionsHow to fill in the forms — step by step
When, what, and in what order to write, explained in STEPs.
StepsCommon mistakes and fixes
What to do about omissions, calculation errors, and missed submissions.
CautionWhat is the year-end adjustment?
The year-end adjustment is the procedure that reconciles the withholding income tax deducted as an estimate from each month's salary over the year (January–December) against your actual annual income tax. In most cases, overpaid tax is refunded, added to your December salary.
Distributed by your company around early November to early December each year. Deadlines differ by company.
You just hand the forms to your company; the tax calculation and settlement are done by the company's staff (or a tax accountant).
Refunds or additional collections are usually made in the December salary or the January salary.
Once the year-end adjustment is complete, a withholding tax slip is issued in January–February. You use it for tax returns and mortgage applications.
Why does overpayment occur?
Settled at
year-end
(basic, social insurance, life insurance, etc.)
(mortgage loan, etc.)
※ If the annual income tax is less than the total of your monthly withholding, you get a "refund"; if it is more, an "additional collection."
The medical expense deduction, Furusato Nozei (outside the one-stop system), the first year of the mortgage loan credit, side-job income exceeding ¥200,000, and similar items cannot be handled in the year-end adjustment. These must be declared in a tax return the following February–March.
Types of declaration forms
For the year-end adjustment you submit mainly three types of declaration forms to your company. Each requires different entries, so check the ones that apply to you.
The basic document of the year-end adjustment. Everyone must submit it. Used to declare dependents, spouse, disability deductions, and so on.
- Your name, address, and My Number
- Name and annual income of your deduction-eligible spouse
- Name, annual income, and relationship of dependents (children, parents, etc.)
- Whether you qualify as a person with a disability, widow(er), single parent, or working student
- Confirmation of whether you receive salary from another company
The form for declaring life insurance premiums, earthquake insurance premiums, iDeCo, and the like. You transcribe and calculate figures from the deduction certificates.
- Life insurance premium deduction (three categories: general, care/medical, and personal pension)
- Earthquake insurance premium deduction
- Social insurance premium deduction (if you pay National Pension or National Health Insurance yourself)
- Deduction for small-enterprise mutual-aid contributions (iDeCo, etc.)
Three declarations combined on one sheet. Everyone fills in the basic deduction. The spousal deduction and income amount adjustment deduction are only for those who qualify.
- Basic deduction application: your estimated total income (not eligible if annual income exceeds ¥25 million)
- Spousal deduction application: your spouse's estimated annual income (not eligible if your own income exceeds ¥10 million)
- Income amount adjustment deduction application: for those with annual income over ¥8.5 million who are raising children or have a special disability, etc.
From the second year of the mortgage loan credit onward, you can claim it in the year-end adjustment using the certificate sent by the tax office. A tax return is needed only in the first year.
- The "Certificate for Special Credit for Housing Loans" sent by the tax office (delivered all at once for up to 10 years the first time)
- The "Certificate of Year-End Balance of Housing Loan, etc." sent by your financial institution
Basic & spousal deductions
This is what you enter on "③ Application for Basic Deduction / Spousal Deduction." The basic deduction applies to everyone; the spousal deduction is judged by your spouse's income.
Basic deduction (everyone qualifies)
| Your estimated total income | Basic deduction | Approx. salary equivalent |
|---|---|---|
| ¥24 million or less | ¥580,000 | Annual salary approx. ¥25.95 million or less |
| Over ¥24 million – ¥24.5 million or less | ¥320,000 | — |
| Over ¥24.5 million – ¥25 million or less | ¥160,000 | — |
| Over ¥25 million | ¥0 (not applicable) | Annual salary over approx. ¥26.95 million |
※ Almost all employees receive the ¥580,000 basic deduction. Just write your estimated total income in "field A" of the form and note the category.
Judging the spousal deduction and special spousal deduction
¥10 million or less?
special spousal deduction
| Spouse's total income (salary equivalent) | Type of deduction | Amount (if your income is ¥9 million or less) |
|---|---|---|
| ¥580,000 or less (annual salary approx. ¥1.23 million or less) | Spousal deduction | ¥380,000 (¥480,000 if 70 or older) |
| Over ¥580,000 – ¥1.05 million or less (–approx. ¥1.70 million) | Special spousal deduction | ¥380,000 |
| Over ¥1.05 million – ¥1.10 million or less (–approx. ¥1.75 million) | Special spousal deduction | ¥360,000 |
| Over ¥1.10 million – ¥1.15 million or less (–approx. ¥1.80 million) | Special spousal deduction | ¥310,000 |
| Over ¥1.15 million – ¥1.20 million or less (–approx. ¥1.85 million) | Special spousal deduction | ¥260,000 |
| Over ¥1.20 million – ¥1.25 million or less (–approx. ¥1.90 million) | Special spousal deduction | ¥210,000 |
| Over ¥1.25 million – ¥1.30 million or less (–approx. ¥1.95 million) | Special spousal deduction | ¥160,000 |
| Over ¥1.30 million – ¥1.35 million or less (–approx. ¥2.00 million) | Special spousal deduction | ¥110,000 |
| Over ¥1.35 million – ¥1.40 million or less (–approx. ¥2.05 million) | Special spousal deduction | ¥60,000 |
| Over ¥1.40 million – ¥1.43 million or less (–approx. ¥2.08 million) | Special spousal deduction | ¥30,000 |
| Over ¥1.43 million (over approx. ¥2.08 million) | Not eligible | ¥0 |
※ If your total income is over ¥9 million and ¥10 million or less, the deduction is smaller than shown above.
Life & earthquake insurance deductions
You enter these on "② Insurance Premium Deduction Application." Simply transcribe the figures from the deduction certificate that your insurer sends around October–November.
The three categories and limits of the life insurance premium deduction
Death insurance, endowment insurance, whole-life insurance, education endowment insurance, etc.
¥40,000
Medical insurance, cancer insurance, nursing-care insurance, disability income insurance, etc.
¥40,000
Personal pension insurance with a "personal pension premium tax-qualified rider."
¥40,000
How to calculate the deduction (new contracts from 2012 onward)
| Annual premiums paid | Deduction formula |
|---|---|
| ¥20,000 or less | Full amount of premiums paid |
| Over ¥20,000 – ¥40,000 or less | Premiums paid × 1/2 + ¥10,000 |
| Over ¥40,000 – ¥80,000 or less | Premiums paid × 1/4 + ¥20,000 |
| Over ¥80,000 | Flat ¥40,000 (limit) |
Earthquake insurance premium deduction
(the full premium paid; cap of ¥50,000)
※ Old long-term casualty insurance premiums (contracts on or before December 31, 2006) have a separate deduction of up to ¥15,000. Check the category on the certificate.
iDeCo & mortgage loan credit
iDeCo (deduction for small-enterprise mutual-aid contributions)
Contributions to iDeCo (individual-type defined contribution pension) are fully deductible from income. Enter them in the "deduction for small-enterprise mutual-aid contributions" field of "② Insurance Premium Deduction Application."
The financial institution operating your iDeCo mails a "Certificate of Payment of Small-Enterprise Mutual-Aid Contributions" around October–November. If you lose it, ask the institution to reissue it.
In the "deduction for small-enterprise mutual-aid contributions" field at the very bottom of "② Insurance Premium Deduction Application," just enter the "total contributions for the year" shown on the certificate.
¥23,000/month (¥276,000/year) if you are not enrolled in a corporate-type DC. Corporate-type DC members: ¥20,000/month (¥240,000/year).
Mortgage loan credit (year-end adjustment from year two)
The mortgage loan credit requires a tax return only in the first year; from the second year onward you can claim it in the year-end adjustment. Enter it on "④ Application for Special Credit for Housing Loans."
After your first-year tax return, the tax office sends up to 13 years' worth of "Certificate for Special Credit for Housing Loans" all at once. Use one each year.
Each year around October–November, the financial institution that made your loan sends a "Certificate of Year-End Balance of Housing Loan, etc." If it is issued electronically, you'll need to download it.
Enter the amount from the balance certificate on the "Application for Special Credit for Housing Loans." Fill in the field where the deduction (balance × 0.7%) is auto-calculated, and submit it to your company.
| Type of housing | Loan cap | Credit rate | Max annual credit | Credit period |
|---|---|---|---|---|
| Certified long-term quality / low-carbon housing | ¥50 million | 0.7% | ¥350,000 | 13 years |
| ZEH-level energy-efficient housing | ¥45 million | 0.7% | ¥315,000 | 13 years |
| Energy-efficiency-standard-compliant housing | ¥40 million | 0.7% | ¥280,000 | 13 years |
| Other housing | ¥30 million | 0.7% | ¥210,000 | 10 years |
| Pre-owned housing (general) | ¥20 million | 0.7% | ¥140,000 | 10 years |
※ For move-in from 2024 onward. Households raising children or young married couples may have their loan cap raised.
If the annual credit exceeds your income tax, the difference is also deducted from the following year's residence tax (up to ¥97,500/year). Even people with little tax can enjoy the benefit of the credit.
Dependent & single-parent deductions
You enter these on "① Dependent Deduction Application." If you support children, parents, grandparents, or others, or if you qualify as a person with a disability or a single parent, you can receive deductions.
Amount of the dependent deduction
| Category of dependent | Condition | Deduction |
|---|---|---|
| General dependent | 16 or older, annual income ¥580,000 or less | ¥380,000 |
| Specified dependent | 19 to under 23 (university students, etc.) | ¥630,000 |
| Elderly dependent (not living together) | Relative aged 70 or older | ¥480,000 |
| Elderly dependent (living together) | Parent aged 70 or older living with you | ¥580,000 |
| Child under 16 | Annual income ¥580,000 or less (not eligible for the dependent deduction) | ¥0 (affects the residence-tax calculation) |
Single-parent deduction & widow(er) deduction
Regardless of marital history, an unmarried, divorced, or bereaved parent with a child (annual income ¥580,000 or less) in the same household. Requires your own annual income to be ¥5 million or less.
A woman who has not remarried after divorce or bereavement and either has a dependent other than a child or was the wife of a deceased husband. Your own annual income must be ¥5 million or less.
When you or a dependent is a person with a disability. General disability ¥270,000, special disability ¥400,000, and a special-disability dependent living with you ¥750,000.
For those enrolled at a university, vocational school, etc., with total annual income of ¥750,000 or less (of which non-employment income is ¥100,000 or less).
If a family member you claim as a dependent — spouse, child, parent, etc. — has salary income exceeding ¥1.23 million a year, they become ineligible for the dependent deduction (or spousal deduction). In particular, get into the habit of checking students' part-time earnings each season. Losing a dependent increases your own tax.
How to fill in the forms — step by step
The year-end adjustment forms are distributed by your company in November–December. Fill them in the order below and submit them to your company by the deadline.
As soon as each deduction certificate arrives, keep them together in one place. You'll submit them to your company along with the year-end adjustment forms.
The first form to fill in is the dependent deduction application. In many cases the content barely changes year to year, but update it if your family situation has changed.
Enter your name, address, and My Number. No seal is required (the company manages the My Number verification documents).
Enter the spouse's name, date of birth, My Number, and estimated income for the year. If income is ¥580,000 or less (part-time salary ¥1.23 million or less), enter them as a "deduction-eligible spouse."
Enter the name, relationship, date of birth, and estimated income of dependents aged 16 or older (children, parents, etc.). Entering a child aged 19–22 in the "specified dependent" field gives a ¥630,000 deduction.
Check the applicable category. Confirm the disability certificate grade or the single-parent conditions before entering.
Fill this in while looking at your life insurance, earthquake insurance, and iDeCo deduction certificates. Because the certificates state a "declared amount," you basically just transcribe those figures.
For each of the three categories — general, care/medical, personal pension — enter the insurer's name, type of insurance, and declared amount. If unsure of the category, check the "deduction category" on the certificate.
Enter the annual premium for earthquake insurance (separated by category from old long-term casualty insurance). Transcribe the "amount of eligible premiums" from the certificate.
Enter the "cumulative contributions for the year" stated on the payment certificate. Since it's fully deductible, no calculation is needed.
This form is submitted by everyone. The main task is calculating and entering your "estimated total income for this year."
If you have only salary income, check the "employment income calculation table." At ¥5 million salary, income is about ¥3.56 million. Enter your total income in "field A" and choose the category (イ–ニ).
If you have a spouse, enter their estimated total income for this year. For part-time earnings only, "annual salary − ¥650,000 (employment income deduction)" is a rough guide to the income.
If you have a mortgage (year two onward), submit the "Application for Special Credit for Housing Loans" together with the "year-end balance certificate."
Submit the completed forms and deduction certificates together to your company's staff. At companies that support electronic filing, submission may be via PDF or an in-house system.
Common mistakes and fixes
Here are the failure patterns in the year-end adjustment and how to handle them. In most cases you can still fix things after the deadline.
If you forget to submit a deduction certificate, the life insurance premium deduction, iDeCo, etc. won't apply and you'll pay extra tax.
If you're still within your company's submission deadline, tell the staff and submit it additionally. After the year-end adjustment is over, you can file a tax return in February–March the following year to claim the deduction and get a refund (within 5 years). If you lost the certificate, ask the insurer or financial institution to reissue it.
If your spouse or a part-time-working child had exceeded the dependent income line but you still listed them on the form, the deduction won't actually apply and you may face additional collection later.
Before filling in the form, check the expected annual income of your spouse and dependents. If part-time earnings in October–December are large, watch whether the year's total exceeds ¥1.23 million. If it looks likely, consult your company's staff and revise the form.
If you mistakenly use, or lose, the deduction certificates issued all at once for 10 years (or 13 years) by the tax office, the procedure gets complicated.
Take out only the sheet you use each year and store the rest carefully. If you lose one, you can have it reissued by submitting an "application for issuance of a Certificate for Special Credit for Housing Loans" at your nearest tax office.
If you miss your company's submission deadline, you won't make the year-end adjustment in time, and the withholding tax slip is issued without your deductions reflected.
If it's before the company finishes the year-end adjustment calculation (usually by mid-December), a late submission may still be accepted. If you don't make it, you can claim the deduction and get a refund by filing a tax return the following year (within 5 years).
You can't declare a side job in the year-end adjustment. If you mishandle the residence-tax handling when filing a tax return for side-job income, your company may find out about the side job.
In the residence-tax section of the tax return, choose "pay it yourself (ordinary collection)." Because declarations about side-job income are made in a tax return, not the year-end adjustment, you don't need to write anything about the side job on the year-end adjustment forms.
If you mix up the three life insurance categories (general, care/medical, personal pension), the deduction won't be calculated correctly and you may lose out.
Check the "type of insurance" or "deduction category" field on the certificate. If it says "medical/care," it's the "care/medical" category; if it says "pension," it's the "personal pension" category. If unsure, checking with the insurer's call center is the surest way.
• Check dependents' expected annual income
• Check that the spouse's part-time earnings won't exceed ¥1.23 million
• Life insurance premium deduction certificate arrives
• iDeCo contribution payment certificate arrives
• Mortgage balance certificate arrives
• The company distributes the year-end adjustment forms
• Fill in the forms and submit them to the company
• Submit the deduction certificates together
• The company performs the year-end adjustment calculation
• Refund or additional collection in the December salary
• Some companies refund in the January salary
• The company issues the withholding tax slip
• Check the content (especially deduction amounts and tax)
• Those who need to file a tax return start preparing
• The medical expense deduction, etc. is claimed in a tax return
• Deductions you forgot in the year-end adjustment can also be handled in the tax return
Learn more in related columns and pages
Life & earthquake insurance premium deductions
Old vs. new systems, the ¥70,000 residence-tax cap, and the deduction formula.
iDeCo's tax-saving effect
Contributions are fully deductible from income. How to declare it in the year-end adjustment.
Tax returns for employees
Deductions you can't recover through the year-end adjustment (medical, first-year mortgage).
Furusato Nozei guide
Choosing between the one-stop exception and a tax return.
FAQ
Which deductions can't be claimed in the year-end adjustment?
The medical expense deduction, the donation deduction (Furusato Nozei portion not using the one-stop system), the first year of the mortgage loan credit, the casualty loss deduction, and others cannot be received in the year-end adjustment; you file a tax return yourself.
What if I forgot to submit a deduction certificate?
Even if you miss your employer's year-end adjustment, you can receive the deduction by filing a tax return (refund claim) yourself the following year. A refund claim is possible for up to 5 years.
Can the mortgage loan credit be done in the year-end adjustment?
A tax return is needed in the first year, but from the second year onward you can receive it in the year-end adjustment by submitting to your company the "Certificate for Special Credit for Housing Loans for Year-End Adjustment" and the "year-end balance certificate."
Sources / official information
This article is based on the official information below. Rules may be revised; please check each official site for the latest details.
- National Tax Agency — Guide to the year-end adjustment (in Japanese)
- National Tax Agency — Tax Answer No.2665 Salary subject to year-end adjustment (in Japanese)
- National Tax Agency — Tax Answer No.1191 Spousal deduction (in Japanese)
- National Tax Agency — Tax Answer No.1140 Life insurance premium deduction (in Japanese)
※ This article is for general information only and is not tax or legal advice. For individual tax matters, consult your local tax office or a licensed tax accountant (zeirishi).