Seoul Traffic Inducement Charge Use & Period Calculator

Review Seoul’s 2026 progressive charge by facility use, ownership and non-use periods, then compare confirmed relief with pending requests and your notice.

Seoul · 2026 assessment · daily planning model

Assessment period: 2025-08-01–2026-07-31. For existing private facilities with unchanged area. New, demolished or extended facilities, public ownership and special exemptions require the authority’s calculation.

1. Building and ownership

2. Uses and non-use periods by area

Enter distinct spaces including allocated common area. Non-use must cover the entire row; split partially vacant space into another row. For unlisted uses or adjusted coefficients, use the authority’s calculation.

Space 1

3. Traffic reduction relief

Do not add individual program rates. Relief applies after non-use reductions. An unapproved rate affects only the all-requests-accepted scenario.

Confirm a Seoul private facility with unchanged area throughout the 2026 assessment year, its classifications and exemptions.

Check a Seoul traffic inducement charge notice

The Korean traffic inducement charge is assessed on owners of facilities that generate traffic congestion.
It has a different basis from privately allocated cleaning, security or building management fees, even when they appear together on a statement.
Article 37 of the Urban Traffic Improvement Promotion Act connects floor area, the unit charge and the traffic inducement coefficient; ownership periods and recognized reductions then need separate review.
Equal-sized spaces can produce different charges because their actual uses and histories differ.

Korea-specific scope: Seoul, 2026 assessment, KRW.
This daily planning model covers existing privately owned facilities with unchanged area throughout the assessment year.
New, demolished or extended facilities, public ownership and special exemptions require the district office calculation.
Results are reconciliation estimates, not final assessments or guaranteed refunds.

The main amount applies confirmed reductions to the entered ownership period.
A separate status identifies unconfirmed ownership proration, and a scenario shows what would happen if all entered requests were accepted.
A large difference points to documents and assumptions worth checking; it does not establish entitlement.

Separate building, owned and chargeable areas

Whole building area

Enter all floors including exempt portions such as qualifying residential and parking areas.
This area determines the facility-size threshold and progressive charge base.
The ordinary threshold is 1,000 m²; a facility inside a housing complex that is not roadside uses 3,000 m².
Multiple buildings on adjoining land with the same owner may be treated as one facility under Article 16 of the Enforcement Decree.
Do not use one small unit as the size of the entire building.

Owned area and calculation rows

Jointly or separately owned facilities have a 160 m² ownership-area threshold under Article 16-2.
Confirm the aggregation of all relevant units and allocated common areas.
The row total cannot exceed the owned area, which cannot exceed the building total.
Omitted areas are not filled automatically: verify that only exempt portions were left out and that every chargeable space is included.

Seoul Ordinance Article 3 includes special cases involving housing-complex amenities and mixed residential buildings, with conditions involving road width, area and committee review.
The calculator does not grant these exemptions from the name or area alone.
Use the confirmed-exempt option only after checking the classification; split partially exempt space into a separate row.

Apply the Seoul progressive unit charge

Seoul Ordinance Annex 3 supplies the post-2020 bands and their progressive formulas.
For building area G, the table gives the total base B(G) before use coefficients.
The highest marginal rate is not applied to every square meter.

2026 Seoul base before traffic inducement coefficients
Whole building area GBase B(G), KRW
Below 3,000 m²G × 350
3,000 through 30,000 m²2,100,000 + (G − 3,000) × 1,400
Above 30,000 m²39,900,000 + (G − 30,000) × 2,000
The 50% adjustment from 700 to 350 KRW applies only when the entire facility is strictly below 3,000 m².
At exactly 3,000 m² the base is 2,100,000 KRW.
A small ownership share in a large building does not qualify the whole building for the small-facility rate.

The planning model divides B(G) by G to obtain a blended unit rate and multiplies that rate by each row area and its coefficient.
This allocates the progressive base in proportion to area.
Confirm how common areas are assigned to uses before comparing with the authority calculation.
Exempt portions remain in the building-size denominator but are omitted from chargeable rows or entered with a confirmed exemption.

Use actual classifications and change dates

Enforcement Rule Article 3-3 uses the actual facility use when it differs from the building register.
Seoul Annex 2 coefficients included here are public/general offices 1.80, neighborhood daily-goods retail 1.68, general restaurants 2.56, the specified hospital category 1.34, academies and training centers 1.42, the specified general-lodging category 1.16 and other neighborhood facilities 1.44.
A general hospital differs from the included hospital category; a large retail establishment differs from neighborhood retail; hotel classifications also matter.

Each row represents a fixed area and allows one use change during the assessment year.
The initial coefficient runs through the day before the change, and the new coefficient begins on the entered change date.
Leave the change date blank to keep the initial use throughout the year.
For unlisted classifications, multiple use changes or coefficients adjusted for public works, obtain the district calculation instead of selecting the nearest-looking option.

Ownership proration and non-use relief are different

Ownership: check the application

The 2026 assessment period is 2025-08-01 through 2026-07-31, or 365 days.
The entered ownership start and end dates are inclusive, and only their overlap with the assessment period is counted.
Confirm the allocation of the transfer date against the ownership record and district instructions; seller and buyer should not both count the same day.
Under Decree Article 23, an acquirer who does not apply for proration inherits liability for the prior ownership period.
Entering a shorter holding period does not itself reduce a notice.

Non-use: duration and evidence

Act Article 38 and Decree Article 24 permit relief for actual non-use of at least 30 days for reasons such as business closure, subject to confirmation.
The model merges overlapping or adjacent intervals for the same space before checking the continuous 30-day threshold.
Two separate 15-day closures do not become one qualifying episode.
When an episode crosses an assessment-year or ownership boundary, the original continuous duration establishes the model threshold and only overlapping ownership/assessment days affect the charge.

Unpaid rent does not necessarily mean non-use: storage, works and common-area treatment require factual review.
Only enter an interval for which the entire row was unused; split out a partially vacant area.
The confirmation checkbox means that the authority confirmed that area and period, not merely that supporting documents are ready.

Compare confirmed relief with a pending scenario

The confirmed estimate deducts recognized non-use first and applies the approved final traffic-reduction percentage to the remaining ownership amount.
Unconfirmed non-use intervals and an unapproved reduction percentage affect only the all-requests-accepted scenario.
The difference indicates an amount to investigate and document, not the probability or guarantee of approval.

Enter one final notified percentage

Seoul Ordinance Article 6 refers to a separate combination formula for multiple traffic-reduction programs, and implementation periods also matter.
Do not simply add the advertised percentages for parking management and vehicle-use restrictions.
Use a final district-confirmed percentage incorporating overlap, participation and implementation duration.
Do not mix the public-ownership 50% reduction, disaster relief or overcrowding-charge exemptions into this private-facility traffic-reduction input.

Worked example: 500 m² of offices in a 5,000 m² building

  1. The building base is 2,100,000 + 2,000 × 1,400 = 4,900,000 KRW.
    The blended rate is 4,900,000 ÷ 5,000 = 980 KRW/m².
  2. With full-year ownership and office use, 980 × 500 × 1.80 = 882,000 KRW.
  3. Confirmed non-use from June 1 through June 30 removes 30 days.
    The daily model displays 882,000 × 335 ÷ 365 as 809,506 KRW, truncating fractions only for display.
  4. A final approved traffic-reduction rate of 20% reduces the remaining amount to a displayed 647,605 KRW.
    These are synthetic verification inputs, not an actual building notice.

For a smaller example, a 2,000 m² building and 200 m² office share owned all year gives 350 × 200 × 1.80 = 126,000 KRW.
The worked-example button loads the first scenario.
Before using those inputs for your own review, recheck every confirmation against your documents.

Steps and result interpretation

  1. Match the assessment year, whole facility size, owner and ownership share against the notice, building register and ownership record.
    Check common-area and multi-unit aggregation.
  2. Enter distinct office, retail, restaurant or other supported spaces and their actual uses.
    Record the first day of the new use where a change occurred.
  3. Enter ownership dates and non-use intervals with their confirmation status.
    Leave confirmation unchecked when there is no authority decision and inspect the scenario difference.
  4. Enter the final traffic-reduction rate and a notice covering the same scope.
    Leave the notice blank if unknown; enter zero only for a real zero-amount notice.
  5. Save the TXT reconciliation or print the page and ask the district office about specific area, use, period or reduction discrepancies.
    Attach the evidence supporting each input.

A positive notice-minus-estimate difference means the notice is larger; a negative difference means the estimate is larger.
Neither is a confirmed refund or additional assessment.
Do not compare a subset of entered rooms with a notice covering the entire ownership share.
The exported report preserves inputs and statuses so the scope remains clear when shared with the district office.

Practical review scenarios

First notice after buying a property

Check whether the notice includes days before acquisition.
Compare the annual amount with the entered ownership-period estimate and prepare the proration application.
A private settlement in the sale contract does not itself complete the administrative application or determine public payment obligations.

Long vacancy and a changed use

Separate vacant space from operating space and avoid double-counting overlapping non-use reports.
Check whether an office-to-restaurant conversion was recorded from the correct date.
Selecting a lower coefficient without confirming the legal classification is not a valid correction.

Frequently asked questions

Is an empty unit automatically exempt?

No.
The duration and the actual unused area must be confirmed.
Lack of rental income alone does not establish non-use relief.

Does the 350 KRW rate apply at exactly 3,000 m²?

No.
The Seoul 50% adjustment applies strictly below 3,000 m².
At exactly 3,000 m² the base is 2,100,000 KRW before coefficients.

Is a 100 m² unit always below the ownership threshold?

Confirm other units owned by the same person and common-area allocations.
The 160 m² rule is not assessed from one unit’s exclusive area alone.

Are overlapping vacancy intervals deducted twice?

No.
Overlapping or adjacent intervals for the same space are merged.
Separate short episodes are not added together to manufacture 30 continuous days.

Can I simply pay only for days after acquisition?

Ownership proration requires an application.
Without it, the acquirer inherits liability for the previous ownership period.
Do not use this estimate to make an arbitrary partial payment.

Why can the result differ from the official notice?

This is a daily model for existing facilities with fractions of KRW truncated for display.
Official monthly calculations, residual days, rounding, common-area allocation and special relief must be reconciled with the district calculation.

Does this determine whether a tenant must pay?

No.
It reviews the public charge assessed on an owner.
It does not determine the validity of lease clauses passing costs to tenants or private settlements.

Can I use this for another city or 2027?

No.
The verified scope is Seoul’s 2026 assessment.
Check local ordinances and the effective dates and transitional rules for later traffic-reduction programs before applying other-year assumptions.

Official evidence and update dates

Verified on 2026-09-24 through the National Law Information OPEN API.
The Act is MST 284063, effective 2026-07-01; the Decree is MST 289713 and the Enforcement Rule is MST 289881, both effective 2026-09-15; the Seoul Ordinance is MST 2070367, effective 2025-10-01.
Seoul Annex 2 supplies the coefficients and Annex 3 supplies the progressive base.
Some September 15 amendments apply only to assessment periods beginning on or after 2026-08-01 or take effect on 2027-08-01, so new program reductions are not applied retroactively to this 2026 assessment.

Prepare the reconciliation and supporting evidence

Under current Decree Article 23, the ownership-proration application runs from receipt of the notice through the payment deadline.
Under Enforcement Rule Article 5, submit the non-use report and evidence within 30 days of receiving the notice.
The ordinary statutory payment period is October 16–31; check the actual deadline and any extension on the notice and with the district office.
Do not reuse the former 10-day ownership-application deadline from an outdated local guide.

  • Notice, itemized calculation, building register and ownership-transfer records
  • Use-change, lease and closure documents, plus dated photographs
  • Electricity/water usage and other non-use evidence requested by the authority
  • Traffic-reduction decision and the calculator TXT reconciliation

Save the report and ask the district office about the specific input causing a difference.
Update those inputs when new evidence arrives and compare the confirmed estimate with the all-accepted scenario again.

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