What is the difference between the santei kiso todoke and the getsugaku henko todoke? How the standard monthly remuneration changes

Bottom line first: The santei kiso todoke is the annual review; the getsugaku henko todoke is a mid-year change when pay moves significantly through a raise or a cut. Both decide the standard monthly remuneration, but their purpose and timing differ.

The standard monthly remuneration determines not only the monthly premiums but also the calculation of future pension benefits. The annual notification is based on remuneration paid in April, May and June, and applies from September through August of the following year. The mid-year notification applies only when three things line up: fixed wages changed, the three-month average differs from the previous grade by two grades or more, and the payment basis days requirement is met in all three months. An increase in overtime pay alone is not, in principle, a trigger.

What is the standard monthly remuneration, and why does it drive premiums?

The standard monthly remuneration is the actual remuneration mapped onto a grade. Monthly health insurance and employees' pension premiums are calculated by applying the rate to this figure, and are shared equally between employer and employee.

What is easily missed is that this is not only about premiums. The standard monthly remuneration under the employees' pension is also used to calculate future pension benefits. The notification is made on the basis of the remuneration actually paid; it cannot be reported at a lower figure at will in order to hold premiums down.

Remuneration includes base pay and allowances such as commuting and housing allowances. Items provided in kind — company housing, for example — may also be valued as remuneration. Our article on company housing and remuneration in kind covers how that valuation works.

Grade tables and premium rates are revised, so this article does not give specific figures. Please check the current ones with the Japan Pension Service or your health insurance provider.

What is the santei kiso todoke, and what is examined for April, May and June?

The santei kiso todoke reports the remuneration received in April, May and June for everyone insured as of 1 July each year. The standard monthly remuneration decided here is used for each month from September through August of the following year. This is called the fixed-time decision.

The filing period is, as a rule, from 1 July to 10 July each year.

One point to watch: what counts is remuneration paid in April, May and June. It is the month of actual payment, not the month of work the pay relates to. At a company that closes the books at month end and pays the following month, the pay for work in March, April and May is what falls in scope. Getting this wrong shifts everything by a month.

Where the standard monthly remuneration calculated from April–June differs by two grades or more from the one calculated on the annual average for July of the previous year through June of the current year, and that difference is expected to arise every year because of the nature of the business, an application can be made for the insurer to calculate on the annual average. Industries whose busy season falls consistently in April to June are the sort of case envisaged. The application requires the prescribed form, documents comparing the situation in a typical year, and the employee's consent.

Table: fixed-time decision versus occasional revision

Item	Fixed-time decision (santei kiso todoke)	Occasional revision (getsugaku henko todoke)
Trigger	Every year (those insured as of 1 July)	A change in fixed wages
Period examined	Remuneration paid in April, May, June	Three months from the first month the changed pay was received
Test	Average of three months	Three-month average differing by two grades or more, in principle
Applies from	September through August of the following year	The fourth month counting from the month of change
Filing	As a rule 1–10 July each year	Promptly, once it applies

Who is covered by the santei kiso todoke?

Everyone insured as of 1 July, plus employed persons aged 70 and over. That second group is easy to overlook, so check it.

The following are excluded:

• Those who acquired insured status on or after 1 June
• Those who left before 30 June
• Those for whom a getsugaku henko todoke revising from July is being filed
• Those for whom notice has been given that an occasional revision is expected in August or September

The last two connect to the section below on what happens when the two notifications overlap.

Whether part-time employees become insured in the first place is outside this article. See our article on social insurance for short-hours employment and our article on the October 2027 expansion of coverage.

What are the 17-day, 15-day and 11-day payment basis days?

Payment basis days are the days the month's remuneration was calculated on. How they are counted depends on the pay form: calendar days for monthly or weekly pay, days worked for daily or hourly pay. Where a monthly salary is reduced for absence, count the days used as the basis for payroll under the wage regulations, less the days absent.

A month that falls below the threshold is not used in the average. There are three thresholds.

Table: which months are used in the fixed-time decision

Category	Months used in the fixed-time decision	If all three months fall below
Ordinary insured persons	Months with 17 or more payment basis days	The previous standard monthly remuneration continues
Short-hours workers (tanjikan shuroysha)	First, months with 17 or more days. If there is none, months with 15 or more but fewer than 17	If all three months are under 15 days, the previous standard monthly remuneration
Short-time workers at specified applicable establishments	Months with 11 or more days	If all three months are under 11 days, the previous standard monthly remuneration

The 15-day threshold is the one most easily missed. Some companies stall on a part-time employee because "April, May and June all fall short of 17 days, so we don't know what to file." In that case you use the months with 15 or more but fewer than 17 days. If all three months fall under 15, the previous standard monthly remuneration simply continues.

The other point that matters: the 15-day treatment is not used in an occasional revision. An occasional revision requires all three months after the change to have 17 or more days (11 or more for short-time workers at specified applicable establishments). The thresholds differ between the fixed-time decision and the occasional revision — that is the takeaway here.

Note that "short-hours worker" (tanjikan shuroysha) and "short-time worker" (tanjikan roudousha) are different categories despite the similar names. A short-hours worker has shorter prescribed hours than a regular employee but is treated as an ordinary insured person. A short-time worker is someone who does not meet the three-quarters standard but becomes insured under the expansion of coverage. For which one applies, see our article on social insurance for short-hours employment.

When is the getsugaku henko todoke required?

When all three of the following line up:

1. Fixed wages changed through a raise, a cut or similar
2. The standard monthly remuneration calculated from the average remuneration over the three months from the month of change differs from the previous one by two grades or more
3. The payment basis days over those three months are 17 or more (11 or more for short-time workers at specified applicable establishments)

The third applies to all three months. If even one falls short, there is no occasional revision.

File promptly once it applies. Unlike the annual notification there is no fixed filing window, so the reliable approach is to make the check a habit at the point payroll is finalised.

What are fixed wages? Does more overtime alone trigger a revision?

Fixed wages are those whose amount or rate is set. The Japan Pension Service gives these examples:

• Raises (base-up) and cuts (base-down)
• Changes to the pay structure (from daily to monthly pay, and the like)
• Changes to the unit rate for daily or hourly pay
• Adding, or changing the amount of, fixed allowances such as housing or position allowances

Items that fluctuate month to month, such as overtime pay, are non-fixed wages. More shifts at an unchanged hourly rate, or more overtime in a busy period, does not on its own produce an occasional revision. The trigger is always a change in fixed wages.

That said, once fixed wages have changed, the three-month average is calculated on total remuneration including overtime pay. Not "overtime is irrelevant," but "overtime alone does not start it, though it counts once it has started."

One more easily-missed point. The direction of movement in fixed wages and in total remuneration must match. Where fixed wages rose but overtime and the like fell so that the three-month average dropped by two grades or more, or where fixed wages fell but overtime and the like rose so that the average climbed by two grades or more, there is no occasional revision. Check whether the movement is up or down on both the fixed wages and the total.

How should "three months, two grades, the fourth month" be read?

The month you start counting from is neither the month the raise was decided nor the month of work it relates to. It is the first month the changed fixed wages were paid.

If fixed wages changed from the April payment, you look at the average of remuneration paid in April, May and June. If that produces a difference of two grades or more, the revision takes effect in the fourth month counting from the month of change — that is, July.

Two grades is the rule, with one exception: where the grade change crosses the upper or lower limit of the standard monthly remuneration, a one-grade difference is enough.

A revised standard monthly remuneration continues until the next fixed-time decision or the next occasional revision.

If the two overlap, which takes priority?

The occasional revision. The Japan Pension Service puts it this way:

Where an occasional revision applies in July, August or September, the standard monthly remuneration determined by that revision takes priority.

Even if the santei kiso todoke has already been filed, file the getsugaku henko todoke if the requirements are met. Conversely, where an occasional revision is expected in August or September, you may give notice to that effect and omit the santei kiso todoke.

If it then turns out that the expected occasional revision does not apply, file the santei kiso todoke promptly. Leaving the omission in place means the year's standard monthly remuneration is never decided.

In practice, before preparing the annual notification, first check whether fixed wages were changed anywhere between April and June. If there was a raise, an occasional revision in July, August or September may apply.

Are there other revisions after childcare or maternity leave?

Yes — the notification of change in monthly remuneration on ending childcare leave, and the equivalent on ending maternity leave. Both allow the standard monthly remuneration to be revised even where an occasional revision would not apply.

There are three main differences from an ordinary occasional revision.

A one-grade difference is enough, not two. The point is to align premiums with reality where someone returns on shorter hours and remuneration falls.

The employee must apply. This is not something the company files on its own: the employer files after receiving the application from the insured person. Tell returning employees that this exists.

The payment basis days requirement is lighter. It is enough that at least one of the three months from the day after leave ends has 17 or more payment basis days (11 or more for short-time workers at specified applicable establishments; for short-hours workers, months with 15 or more but fewer than 17 days are used if all three months fall under 17). The revision takes effect from the fourth month.

One caution: where childcare leave begins the day after maternity leave ends, the maternity-leave application cannot be made. The revision on ending childcare leave is then considered once that leave finishes.

This is a different scheme from the exemption of premiums during maternity and childcare leave. The exemption removes the premiums themselves; this revision aligns the standard monthly remuneration with reality after the return.

So which pay changes should the company be checking?

In order, there are seven.

1. Finalise the pay actually paid in April, May and June, and check the payment basis days
2. File the santei kiso todoke, as a rule between 1 and 10 July
3. Whenever fixed wages change, mark the month the changed pay was first paid
4. Once three months of pay from that month are final, check the payment basis days, whether fixed wages and total remuneration moved in the same direction, and whether the difference is two grades or more
5. If it applies, file the getsugaku henko todoke promptly, revising from the fourth month
6. Where an occasional revision applies in July, August or September, remember that it takes priority over the annual notification
7. Where an employee is returning from maternity or childcare leave, tell them they can apply for the revision on ending leave

Whether the third becomes a habit largely decides whether filings get missed. Mark the month of payment, not the month the raise was decided.

What can 四葉社会保険労務士事務所 (Yotsuba Certified Social Insurance and Labor Consultant Office) do?

What we take on is the filings and the checking that comes before them.

• Preparing and filing the santei kiso todoke and getsugaku henko todoke
• Building the internal workflow for checking whether a pay change triggers an occasional revision
• Organizing how wage regulations and allowance design bear on fixed wages
• Organizing the use of electronic filing
• Identifying the filings needed when someone returns from maternity or childcare leave

The Health Insurance Act appears at item 21 of Appended Table 1 of the Certified Social Insurance and Labor Consultant Act, and the Employees' Pension Insurance Act at item 24. Preparing applications under those laws is work under Article 2, paragraph 1, item 1 of that Act, and acting on the filing procedure is work under item 1-2 of the same paragraph.

We do not handle the following.

• Tax treatment of premiums, and year-end adjustment → we connect you with a tax accountant (Zeirishi)
• Negotiation or litigation once insured status or entitlement to benefits becomes contested → not handled by this office; we refer you to a lawyer (Bengoshi)

On whether to file in-house or outsource, see our article on bringing payroll in-house with freee.

四葉不動産株式会社, 四葉行政書士事務所, and 四葉社会保険労務士事務所 each accept work as separate, independent business entities. Where we introduce another professional, we do so on the basis that you contract with them directly, and we receive no referral fee.

Consultations are free of charge. Please also see our services and how we work.

Frequently asked questions

Q. By when must the santei kiso todoke be filed?
A. The filing period is, as a rule, from 1 to 10 July each year. It covers everyone insured as of 1 July plus employed persons aged 70 and over, excluding those who acquired insured status on or after 1 June, those who left before 30 June, those for whom a July revision is being filed, and those for whom notice of an expected August or September revision has been given.

Q. Does a month with a lot of overtime mean a getsugaku henko todoke is required?
A. In principle no. An occasional revision starts from a change in fixed wages, so movement in non-fixed wages such as overtime pay does not on its own meet the requirements. That said, once fixed wages have changed, the three-month average is calculated on total remuneration including overtime. And where fixed wages and total remuneration moved in opposite directions, there is no occasional revision.

Q. A part-time employee's payment basis days fall short of 17 in all three months. What happens?
A. In the fixed-time decision, months with 15 or more but fewer than 17 days are used. If all three months fall under 15, the previous standard monthly remuneration continues. Note that this 15-day treatment belongs to the fixed-time decision: an occasional revision requires all three months to have 17 or more days (11 or more for short-time workers at specified applicable establishments).

Q. A raise moved the grade by only one. Is no filing needed?
A. In principle none, since an occasional revision requires two grades or more. The exception is a grade change crossing the upper or lower limit of the standard monthly remuneration, where one grade is enough. Separately, the revision on ending maternity or childcare leave works on a one-grade difference and requires the employee's own application.

Sources for this article

• Japan Pension Service, "Fixed-time decision (santei kiso todoke)" — covers everyone insured as of 1 July plus employed persons aged 70 and over; decided on remuneration received in April, May and June and applied from September through August of the following year; payment basis days of 17 or more for ordinary insured persons, months with 15 or more but fewer than 17 days for short-hours workers where no month reaches 17, and 11 or more for short-time workers at specified applicable establishments; where all months fall below, the previous standard monthly remuneration is used
• Japan Pension Service, "Determination by the insurer" — calculation on the annual average where the standard monthly remuneration from April–June differs by two grades or more from that based on July of the previous year through June of the current year, and that difference is expected to arise every year because of the nature of the business
• Japan Pension Service, "Filing the santei kiso todoke for FY2026" — the FY2026 filing period is 1 to 10 July (Friday). As a rule the period is 1 to 10 July each year
• Japan Pension Service, "Occasional revision (getsugaku henko todoke)" — the three requirements; revision from the fourth month counting from the first month the changed pay was received; a one-grade difference suffices where the change crosses the upper or lower limit; examples of fixed wages
• Japan Pension Service, FAQ on which takes priority between the santei kiso todoke and a July/August/September getsugaku henko todoke — "Where an occasional revision applies in July, August or September, the standard monthly remuneration determined by that revision takes priority."
• Japan Pension Service, "Those expecting an occasional revision in August or September" — file the getsugaku henko todoke if the requirements are met, and the santei kiso todoke promptly if it turns out they are not
• Japan Pension Service, "Filing the notification of change in monthly remuneration on ending childcare leave" — on the employee's application, revised from the fourth month based on the average over the three months from the day after leave ends; a one-grade difference; at least one of the three months with 17 or more payment basis days
• Japan Pension Service, "Notification of change in monthly remuneration on ending maternity leave" — the same structure; no application where childcare leave begins the day after maternity leave ends
• Certified Social Insurance and Labor Consultant Act (社会保険労務士法, Act No. 89 of 1968), Article 2 paragraph 1 item 1 (preparing applications) and item 1-2 (acting on the filing procedure); Appended Table 1 item 21 (Health Insurance Act) and item 24 (Employees' Pension Insurance Act)
• Grade tables and premium rates are revised, so no specific figures are given in this article
• Public materials confirmed on 20 August 2026

This article does not determine whether any particular case qualifies. 四葉社会保険労務士事務所 can advise on preparing and filing the santei kiso todoke and getsugaku henko todoke, building the internal workflow for checking pay changes, organizing wage regulations and allowance design, and the use of electronic filing. Tax treatment of premiums and year-end adjustment are matters we connect you with a tax accountant (Zeirishi) for. Negotiation or litigation once insured status or entitlement becomes contested is not handled by this office; we refer you to a lawyer (Bengoshi). If a different professional is needed, each is contracted separately, and there is no referral fee. Fees are set out in the fee schedule, and frequently asked questions are collected in the FAQ.

This article is general information. Individual determinations are made by a qualified professional after a consultation, in light of individual circumstances. Written by Joji Uramatsu (Shakai Hoken Roumushi, Gyoseishoshi, Registered Real Estate Transaction Specialist).