What do provisional and final construction premiums settle?
South Korean construction businesses using annual self-reporting need separate records for the previous year’s actual remuneration and the current year’s estimate.
The 2025 final premium applies the rates for that year to remuneration paid or decided to be paid.
The 2026 provisional premium budgets this year’s contributions using the applicable remuneration bases and 2026 rates.
A difference between the previous year’s prepayments and its final premium creates a top-up or refund review; it is separate from the new year’s provisional premium.
This calculator helps construction owners and accounting staff reconcile an agency-verified reporting unit before filing.
It uses annual business remuneration and payment records rather than one worker’s monthly payroll or daily take-home pay.
Results do not establish an accepted filing or coverage approval.
Top-ups and refund candidates remain separate so an expected refund does not conceal cash needed for another payment.
Korean filing year 2026
The supported combination is 2025 final settlement and 2026 provisional premiums.
The regular statutory filing and payment reference is March 31, 2026, which may already have passed when you review this guide.
This tool compares filing budgets and does not determine late fees or today’s unpaid balance.
It covers Korean rules and does not translate the formula into another country’s insurance system.
Verify the reporting unit and supported business scope
Blanket, individual or approved subcontractor
Collection Act Article 8 addresses blanket business coverage and Article 9 addresses responsibility in contracting arrangements.
A subcontractor does not automatically become a separate payer merely because work passes through several contractors.
Verify agency approval and match remuneration and payments to the same reporting unit.
Continuing annual self-reporting
The model supports construction businesses continuing from the beginning through the end of 2026.
Verify that an individual project is an eligible continuing business.
Midyear establishment or closure, short projects and midyear rate changes withhold settlement amounts and schedules.
Monthly-assessed businesses and other schemes require their own procedures.
Articles 17 and 19 contain different references for establishment within the year, including 70 days after establishment, the day before a short project ends, and 30 days after insurance closure.
Decree Article 22 excludes businesses established on or after July 1 and fixed-duration projects shorter than six months from installments, and changes the allocation for certain midyear starts.
These cases are not calculated using this tool’s four equal annual installments.
Check the applicable agency instructions instead.
Remuneration bases reflect each insurance’s coverage
Unemployment-benefit remuneration
Enter remuneration subject to the unemployment-benefit premium.
Article 13 exceptions, including qualifying new employment after age 65, depend on actual insured history; age alone does not exclude every older worker.
In this ordinary model, unemployment remuneration cannot exceed stability and development remuneration.
An inverted input is withheld so you can review coverage and the reporting unit.
Employment-stability and skills-development remuneration
Enter the separate base for the employer’s stability and skills-development contribution.
Some remuneration excluded from unemployment contributions can remain in this base, so the two figures are not automatically synchronized.
Reconcile head-office and site allocation, exempt income and duplication against payroll and agency records.
Accident-insurance remuneration
Use the verified accident-insurance base for the selected reporting unit.
Coverage and site allocation can differ from Employment Insurance.
Do not mix separate construction-equipment labor-provider filings into ordinary employee remuneration and apply this model’s general rate to the combined amount.
Article 19 includes remuneration decided to be paid, not only amounts already disbursed.
When outsourced remuneration cannot be established, Article 13(6) and Decree Article 11 require separate review of labor-ratio conditions and approved subcontractor exclusions.
This calculator does not multiply construction contract values by an automatic labor ratio.
Use verified remuneration; the KRW 1 trillion input limit is a product limit rather than a legal exemption or filing threshold.
Separate total Employment Insurance from employer cost
Annual employment premium formula
Total employment premium = unemployment remuneration × 1.8% + development remuneration × verified development rate.
Employee share = unemployment remuneration × 0.9%.
Employer employment share = unemployment remuneration × 0.9% + development premium.
The amount remitted to the agency includes the employee share, so it exceeds the employer’s own employment cost.
Stability and development contribution categories under Collection Decree Article 12| General employer category | Development rate |
|---|
| Fewer than 150 regular workers | 0.25% |
| 150 or more, priority-support enterprise | 0.45% |
| 150–999, outside that priority-support category | 0.65% |
| 1,000 or more outside priority support, or national/local government | 0.85% |
Article 12 also covers domestic-business headcount aggregation, contractor and approved subcontractor rules, and deferrals after workforce growth.
Do not determine the rate from one site’s headcount alone.
Use the agency’s applicable value separately for 2025 and 2026.
Choosing a rate in this interface does not approve priority-support status or a deferral.
Enter the final accident rate including commute coverage
3.56% is a standard reference
MOEL Notices 2024-77 and 2025-91 set the 2025 and 2026 construction industry rate at 35‰ and ordinary commuting coverage at 0.6‰.
In percent units, 3.5% + 0.06% = 3.56%.
Accident premium = accident remuneration × verified final total rate.
The standard construction rate is not automatically every business’s final applicable rate.
If the agency approved an individual experience adjustment, enter the final total incorporating that adjustment and the applicable commute component.
Adding another 0.06% to an already total rate double-counts commute coverage.
Leave rate verification unchecked until any exception or adjustment is reconciled.
The tool does not automatically reclassify head-office clerical operations as a construction site.
The 2025 notice applies from January 1 through December 31, 2025; the 2026 notice applies from January 1 through December 31, 2026.
Verify the new notice for 2027 rather than extending these constants into the following year.
Reconcile declared provisional amounts and actual payments
Top-up uses the declared amount
Current Form 23 uses field ③ final premium minus field ④ previous provisional declared amount for the additional premium.
A final premium above the declared amount creates the final top-up budget.
Record actual installments separately to reconcile them with the declaration.
Refund candidate uses the paid amount
The form’s excess amount uses field ⑤ actual payments minus field ③ final premium.
A positive amount is a refund candidate subject to separate agency approval and timing.
Existing arrears are reviewed against their original notices, separately from the form’s final top-up.
Only matching ordinary prior-year ledgers are calculated
This calculator requires each insurance’s 2025 declared provisional amount to match actual payments, with no prior reductions, arrears, refunds, credits or other adjustments.
In that case, both top-ups and excess amounts can be checked against the same balance.
A mismatch or special history withholds amounts for separate agency settlement review.
Do not invent payments for reductions or subtract refunds simply to force the two inputs to match.
Use payment confirmations and bank evidence, and separate other charges such as wage-claim levies from insurance amounts.
An employment top-up and an accident refund candidate are not automatically offset here.
The arithmetic net is explanatory and is shown separately from payment cash.
What happens when this year’s estimate is 70–130%?
Previous remuneration under Decree Article 21
When the current estimate is at least 70% and at most 130% of the previous year’s remuneration, use the previous remuneration as the provisional base.
Both boundaries are included.
Outside the range, use the current estimate.
This rule selects remuneration, not the previous year’s premium amount: apply the current year’s rates to the chosen bases.
The calculator shows the ratio and applied base separately for unemployment, development and accident contributions.
Changes in coverage or site allocation require separately verified bases.
When the previous base is zero, no comparison ratio is shown and the current estimate is used.
Ratios are rounded for display, but boundary decisions use the original remuneration values so an estimate just above 130% does not enter the included range.
A 10% increase with a rate change
Previous remuneration of KRW 100,000,000 and a current estimate of KRW 110,000,000 give a 110% ratio and an applied base of KRW 100,000,000.
If the development rate changes from 0.25% to 0.45%, that contribution changes from KRW 250,000 to KRW 450,000 despite the unchanged applied base.
Copying the prior premium would miss the difference.
Compare installments with a verified 3% full-payment reduction
Four provisional installments
A continuing eligible business divides its annual provisional premium into four quarters.
Form 23 instructions give equal amounts to installments two through four and allocate the remainder to the first installment.
The tool preserves formula decimals, so verify actual filing and payment truncation separately.
The first cash requirement also includes the entire previous-year final top-up.
Do not divide the final shortfall into these four installments.
Verify the agency’s installment application procedure.
Timely full provisional payment
Act Article 17(4) and Rules Article 18-2 provide a 3% reduction for an installment-eligible business paying the full provisional premium by the applicable deadline.
The comparison applies it only when the conditions are verified.
Selecting full payment, or reviewing a past deadline, does not itself establish eligibility.
The final top-up receives no reduction.
Statutory 2026 installment calendar references for continuing construction businesses| Period | Statutory reference · holidays unadjusted | Cash composition |
|---|
| 1 | 2026-03-31 | First provisional share + entire final top-up |
| 2 | 2026-05-15 | Second provisional share |
| 3 | 2026-08-15 | Third provisional share |
| 4 | 2026-11-15 | Fourth provisional share |
August 15 and November 15 fall on holidays in 2026, so verify the actual payment notice dates.
These calendar references are not final legal deadlines adjusted for public holidays, temporary holidays or individual extensions.
The schedule does not subtract current-year payments: use a separate current-year ledger to reconcile money already paid.
Check the settlement and cash with a fictional example
Assume a verified continuing business with KRW 100,000,000 in each 2025 remuneration base and KRW 110,000,000 in each 2026 estimate.
Both years use a 0.25% development rate and a verified total accident rate of 3.56%.
Four previous-year ledger rows each contain KRW 450,000 employment and KRW 1,000,000 accident payments: totals are KRW 1,800,000 and KRW 4,000,000.
The prior provisional declarations match those amounts and have no reductions, arrears, refunds, credits or adjustments.
These are fictional formula fixtures rather than real site records.
Worked example with KRW 100 million previous bases and 110% estimates| Output | Amount (KRW) | Interpretation |
|---|
| 2025 final employment premium | 2,050,000 | 1,800,000 unemployment + 250,000 development |
| 2025 final accident premium | 3,560,000 | 100,000,000 × 3.56% |
| Employment top-up | 250,000 | Declared and paid amounts both 1,800,000 |
| Accident refund candidate | 440,000 | Does not automatically reduce payment cash |
| 2026 provisional premium total | 5,610,000 | 110% estimate uses previous bases |
| First cash with installments | 1,652,500 | 1,402,500 provisional + 250,000 final top-up |
| Verified full-payment reduction | 168,300 | 5,610,000 × 3% |
| First cash with reduced full payment | 5,691,700 | 5,441,700 provisional + 250,000 final top-up |
The arithmetic net of the two settlement differences is −190,000 KRW, but it is not approved refund cash.
The KRW 250,000 top-up remains payable in this comparison.
Annual cash is KRW 5,860,000 with installments and KRW 5,691,700 with the verified reduction.
Full payment saves KRW 168,300 over the year but requires KRW 4,039,200 more at the first reference date.
Compare that timing difference with the business’s funding needs.
Filing preparation and practical scenarios
- Verify insurance relations, the blanket registration, contractor approvals and head-office/site allocation.
- Reconcile 2025 payroll, exempt income and coverage; enter the verified bases and final rates.
- Reconcile each declared provisional amount with payment confirmations.
Verify a matching ordinary ledger without reductions, arrears, refunds, credits or adjustments; otherwise prepare separate agency settlement records.
- Enter 2026 remuneration estimates and rates, then check the applied 70–130% bases.
- Verify installment applications and reduction conditions, compare cash schedules and save the TXT ledger.
- Check actual notice dates, billing truncation and separate charges before filing through the official service.
A refund candidate and a shortfall coexist
Reserve the shortfall and first provisional share without reducing them for an unapproved refund.
Update the real cash ledger only after the agency processes a refund or credit.
Construction volume or staffing changes
Do not use the growth in construction contract value as an automatic insurance-premium growth rate.
Review covered remuneration and the 70–130% applied bases, then calculate with the verified current-year rates.
Frequently asked questions
How does this differ from a general social-insurance calculator?
Use annual remuneration and payments for a verified construction business unit, rather than an individual monthly wage.
The tool compares previous final settlement and current provisional payment budgets.
It does not calculate pension or health insurance.
Is the entire employment premium an employer cost?
No.
The 1.8% unemployment contribution includes employee 0.9% and employer 0.9%.
Development premiums are employer contributions.
The interface separates the total agency payment from the employer’s own cost.
Should I add another 0.06% for commuting coverage?
Enter the final total accident rate.
Do not add commuting coverage again to the standard 3.56% or an agency-confirmed total.
Verify individual experience adjustments and any exceptions against agency records.
Do I always use the current remuneration estimate?
Use the previous base when the estimate is at least 70% and at most 130% of it, including both boundaries.
Otherwise use the current estimate.
A zero previous base has no ratio and uses the current estimate.
Can an accident refund automatically pay an employment shortfall?
The tool does not automatically offset them.
Agency refund and credit decisions control actual cash timing.
The arithmetic net is not a payment amount.
Prior reductions, arrears, refunds, credits or a declared/paid mismatch withhold amounts.
Review separate agency settlement records.
Does choosing full payment always reduce premiums by 3%?
Verify that the business can use installments and paid its full provisional premium by the applicable deadline.
An unverified reduction is compared as zero.
The final top-up receives no reduction, and a past deadline does not create automatic eligibility.
Can I use this for a midyear start, closure or short project?
This model is an annual four-quarter budget for continuing businesses.
Midyear establishment or closure, short projects and midyear rate changes withhold results.
Separately verify 70-day and 30-day references, day-proportional allocation and installment restrictions.
Does saving a TXT file submit my filing?
Saving preserves inputs and verification items.
Submit the actual filing through COMWEL or the relevant agency process.
Displayed decimal places and rounding are not the agency’s statutory filing or payment truncation rule.
Official sources, verification date and next filing action
Primary evidence was checked on 2026-10-08 through the official Korean law OPEN API.
Relevant versions are Collection Act MST285369 effective 2026-10-08, Decree MST280527 effective 2025-12-23 and Rules MST287859 effective 2026-07-01.
Current Form 23 confirms declared amounts for top-ups, paid amounts for excess, separate arrears notices and first-installment remainder allocation.
Articles 17 and 19 were compared with earlier Act MST247481 to confirm the same remuneration and filing-reference provisions.
The 2025 PDF and 2026 HWPX notices supplied the accident rates and their effective periods.
Recheck reporting units, labor-ratio conditions, development categories and deferrals, final experience-adjusted accident rates, refunds and credits, notice dates and truncation for each filing.
The 2022 agency webzine’s subcontract labor ratios and construction-equipment tables were not copied into automatic 2026 constants.
Entered remuneration and ledger notes are not sent to a server or GA; only the standard page analytics apply.
Save the ledger and verify it with the agency
Prepare payroll, payment confirmations, applicable rates and approval evidence alongside the saved ledger.
Keep refund candidates separate from top-ups and verify actual notice dates before filing.
COMWEL inquiries: 1588-0075.
Prepare the official COMWEL filing