Organize past support amounts and the timing of a Korean claim
After raising children alone following a divorce, a caregiver may need to reconstruct years of costs, changing incomes and occasional payments before discussing a contribution from the other parent.
This calculator organizes those periods and estimates a reference allocation for each child, alongside the timing questions that need legal review.
It uses period-specific income and the child’s age at the time, rather than applying current income and age to every past year.
First distinguish an unfixed right to seek a contribution from a payment claim already fixed by agreement or adjudication.
The worksheet helps prepare a consultation; it does not determine a legal ceiling, a court award, success in proceedings or the amount that can actually be collected.
All amounts are KRW, and the jurisdiction is Korea under sources checked in 2026.
Decisions this can support
- Prepare a past-support claim around the time a child becomes an adult.
- Identify which child’s limitation history needs attention first.
- Compare a proposed settlement with period-based reference amounts and identify missing records.
- Separate preparation of an unfixed claim from enforcement of an already fixed payment obligation.
Korean legal scope and the decisions checked in 2026
Civil Act Article 837 governs arrangements for children’s care and cost sharing following divorce.
Supreme Court decision 92Seu21, dated 1994-05-13, recognizes appropriate contributions toward past care costs, subject to special circumstances, and explains factors affecting the allocation.
It does not require every historical expense to be charged to the other parent.
Limitation references use Supreme Court en banc decision 2018Seu724, dated 2024-07-18, and the 10-year period in Civil Act Article 162(1).
The decision concerns past support between divorced parents whose specific content and scope have not been fixed by agreement or family-court adjudication.
For that unfixed right, time does not run during minority; it starts when the child becomes an adult and the ordinary duty of child support ends.
Paternity proceedings, a child’s own maintenance claim, foreign law, deemed majority following a minor’s marriage, death and other special facts need separate review.
Selecting another claim relationship or a special end-of-duty circumstance withholds the limitation date.
Records to prepare and what the inputs mean
Birth dates and actual care
Check birth dates against family records and enter the actual periods of sole care.
The divorce date does not necessarily mark the first day of that care.
Overlapping dates for the same child are rejected, and gaps between entered periods are not filled automatically.
Each parent’s income at the time
Enter each parent’s gross monthly income for that period in KRW.
Prepare relevant salary, business, rental, interest and pension records.
Current income is not treated as historical income; split periods for employment, unemployment, leave or other changes.
The standard and payments received
The monthly standard is the combined parental cost for one child before applying the payer’s income share.
Entering an already allocated payment as the manual standard applies the share twice.
Received payments must relate to this child and the periods entered, excluding other children or omitted periods.
Agreements and limitation history
Check agreements, support records, mediation records, adjudications, filings and receipts.
Acknowledgment, seizure, partial payment and demands can require individual interpretation.
Choose the unknown option if records are unclear: amounts can be organized while the limitation date remains withheld.
Where the 2021 guideline table is used
Automatic estimates use the average support values in the Seoul Family Court table announced on 2021-12-22 and implemented from 2022-03-01.
This is not a newly issued 2026 table.
The reference is one child in a two-child household, with age bands 0–2, 3–5, 6–8, 9–11, 12–14 and 15–18, and columns for combined parental monthly income.
At combined monthly income of KRW 5,000,000, the standard for ages 12–14 is KRW 1,423,000 per month.
The KRW 2,000,000 and KRW 12,000,000 thresholds enter their respective higher columns exactly.
KRW 1,999,999 is not rounded up into the KRW 2,000,000 column.
Both the income boundary and the historical birthday matter.
Before 2022-03-01: use a verified manual standard
The current table is not applied automatically to earlier years.
Enter a combined parental monthly standard supported by the applicable historical records.
Split a period crossing 2022-03-01 to use manual and automatic methods separately, or use a verified manual standard for the whole period.
An invented monthly amount is not evidence for a real claim.
Allocation and optional reduction formulas
Reference allocation
Payer share = payer income ÷ combined parental income
Row allocation = monthly standard × payer share × included days ÷ calendar days in that month
Net reference = max(sum of row allocations − received payments, 0)
Your optional reduction assumption
Scenario reference = max(gross reference × (1 − reduction percent ÷ 100) − received payments, 0)
There is no default reduction rate.
Enter a percentage only to compare your own settlement assumption; it does not predict a usual court reduction or a probability of success.
Applying a reduction after first subtracting payments produces a different result, so clarify the formula during discussions.
If both incomes are zero, the share cannot be computed and the amount is withheld.
This does not establish an absence of support responsibility.
If received payments exceed the gross reference, the remaining arithmetic amount is zero; the tool does not determine that any excess must be repaid.
Period boundaries and partial-month assumptions
Entered start and end dates are inclusive.
The reference date itself and later days, and the ordinary majority date and later days, are excluded from past minor-care amounts.
Rows split at calendar-month boundaries and birthdays that change an age band.
Gaps between income periods are not assumed to be additional eligible care.
A partial-month example
From 2022-03-16 through 2022-03-31 there are 16 included days, so the allocation uses 16/31 of the March amount.
February 2024 has 29 days, so that month is not divided by 28.
This calendar-day proration is an arithmetic planning assumption, not a mandatory court rule.
Fractional won are retained across rows and the gross amount is rounded once per child.
Majority dates and raw limitation endpoints
Current Civil Act Article 4 sets majority at 19.
The age changed from 20 to 19 on 2013-07-01, so age 19 is not retrospectively applied to every older child.
Someone already 20 before that change uses the former majority date; someone at least 19 but not yet 20 at commencement uses the transition date.
- Born 1993-06-30: ordinary majority on 2013-06-30.
- Born 1993-07-01 or 1994-07-01: transition majority on 2013-07-01.
- Born 1994-07-02: ordinary majority on 2013-07-02.
- Born 2008-02-29: the 19-year period ends after February in a non-leap year, giving an attainment date of 2027-03-01.
The raw endpoint assumes the limitation period begins at midnight on the ordinary majority date and applies the calendar-period rules of Civil Act Articles 157, 159 and 160 for 10 years.
For a birth date of 2000-10-29, ordinary majority is 2019-10-29 and the raw endpoint before holiday adjustment is 2029-10-28.
Civil Act Article 161 may extend an endpoint falling on a Saturday or public holiday; verify this and case-specific facts separately.
The displayed date is not a confirmed final filing deadline.
Decision 2018Seu724 does not restart every claimant’s clock for another 10 years from its decision date, 2024-07-18.
Review each child’s majority date and the actual history.
The 90-day marker is a preparation reminder, not a legal grace period or permission to wait.
From records to a consultation worksheet
- Set the reference date and claim relationship, then enter each child’s birth date.
- Select whether an amount has been fixed and whether any limitation-related history exists.
- Enter care periods and the parents’ historical incomes, splitting periods when income changes.
- Before 2022-03-01, enter a verified combined parental monthly standard manually.
- Deduct payments received for that child and those periods; add a reduction assumption only if useful.
- Inspect the child-specific status and rows, then save a TXT worksheet or print for consultation.
The tool supports up to 5 children and 12 periods per child.
Use transfer records and agreements to avoid deducting the same payment for multiple children.
Input errors hide totals.
If a valid input still leaves a child’s amount uncomputable, the all-child total is also withheld so that a partial amount is not mistaken for the complete estimate.
Hypothetical example: 12 months and received payments
Assume a child born on 2010-01-01, cared for from 2022-03-01 through 2023-02-28.
Payer income is KRW 3,000,000 per month, caregiver income KRW 2,000,000, and received payments KRW 2,000,000.
The example reference date is 2026-10-28; these are hypothetical facts.
Hypothetical 12-month past support allocation and reduction scenario| Item | Amount or percentage |
|---|
| Monthly standard, ages 12–14 | KRW 1,423,000 |
| Payer share / monthly allocation | 60% / KRW 853,800 |
| Gross reference for 12 months | KRW 10,245,600 |
| After deducting KRW 2,000,000 received | KRW 8,245,600 |
| 20% gross reduction, then payments deducted | KRW 6,196,480 |
The 20% is an illustrative user assumption, not a court reduction rate.
The example child is still a minor on the reference date, so the unfixed claim clock is shown as not running.
An amount already fixed by agreement or adjudication requires a different limitation review despite the same birth date.
Circumstances that can change an actual allocation
Property arrangements and fairness
Supreme Court decision 2023Seu637, dated 2024-10-08, explains that property division and property agreements may need examination for their contribution to the children’s care.
Bring records of housing or assets left for care and direct education or treatment payments, separately from ordinary cash transfers.
The tool does not convert an asset value into a cash support credit automatically.
Adjustments are not automatic
Property, number of children, location, substantial treatment costs, reasonable special education expenses and individual rehabilitation can require case-specific assessment.
The automatic mode uses table averages without applying a fixed one-child uplift or other automatic factor.
Avoid double-counting special expenses or applying today’s spending to every historical period.
A passed raw endpoint calls for individual limitation review.
One calculated date cannot establish the existence or effect of acknowledgment, a filing, seizure or suspension.
A demand or certified letter does not automatically start a fresh 10-year period in every case; check the documents and dates.
Frequently asked questions
Can I recover the entire calculated amount?
The reference is not automatically a court award.
Decision 92Seu21 calls for individual assessment of care circumstances, historical costs, incomes, property, awareness of the duty and fairness.
Does minority stop limitation for every support payment?
The not-running message assumes an unfixed past-support right whose content and scope have not been established by agreement or adjudication.
Already fixed periodic payment claims require separate review.
Is the amount zero after 10 years of adulthood?
The arithmetic reference is retained after the raw endpoint.
Holidays and case history still need review; the screen does not determine expiry or collectibility.
Can automatic mode cover years before 2022?
Automatic mode starts on 2022-03-01.
Enter a verified combined parental standard for earlier periods manually, and retain its source and applicable dates with the worksheet.
How should occasional payments be entered?
Add payments attributable to this child and the entered periods.
If transfers mix several children or property division, verify the agreement and records before allocating them.
Which reduction percentage should I choose?
There is no statutory or recommended default reduction here.
Leave it blank or enter a percentage for your own settlement comparison; do not interpret it as a predicted court rate.
What if both incomes are zero or records are unclear?
Two zero incomes withhold the amount.
Do not replace unknown income with zero and infer no duty; gather historical income, assets and actual cost records for review.
Does saving TXT replace a filing or preserve the claim?
TXT and printouts organize assumptions, formulas and rows for consultation.
They do not submit a court claim or interrupt limitation; confirm the procedure, required documents and completed filing separately.
Official sources and verification date
Sources were checked on 2026-10-28 through the National Law Information OPEN API.
The current Civil Act was ID001706, MST284415, effective 2026-03-17.
Checks cover Article 4, Articles 157–162, Article 166, Article 168 and Article 837, plus Act No.10429 and the majority-age change effective 2013-07-01.
Recheck new guideline publications, precedent changes and the facts applicable to the actual case.
Verify the records and prepare the next step
Gather each child’s agreements, court documents and payment records.
If timing is unclear or a raw endpoint is near, consult the Child Support Agency or a Korean legal professional promptly.
Saving a worksheet can clarify the calculations but does not itself preserve a right.
If proceeding with a claim, confirm jurisdiction, filing method and completed receipt.