Review Korean duty already paid using FTA retroactive preference
An importer may pay ordinary duty because origin evidence was unavailable at clearance, then obtain valid evidence later.
Korean retroactive preferential treatment provides a procedure to review the applicable rate and paid tax.
This Korea-based 2026 calculator compares a verified preferential rate with paid duty while the goods remain with the importer, alongside the additional cost of applying.
Import retailers and buyers of expensive goods need to compare the filing window and actual costs as well as the headline refund.
Certificate issuance, translation and agent fees can consume the recovery.
Review both cash after costs and benefit after time costs for direct filing and filing through an agent.
Initial dates and amounts are fictional practice inputs and do not establish a product rate or agreement entitlement.
The next action
Save the review and assemble the import declaration, origin evidence, previous refund records and quotes.
Check and submit the required documents with the clearance customs tax-review office.
Saving a report or viewing a result does not submit a claim.
Distinguish the ordinary one year from the 45-day exception
Ordinary application
FTA Customs Act Article 9(1) allows an importer who did not claim preference before acceptance to apply within one year from import declaration acceptance.
The purchase date and the day the certificate reaches you are not the ordinary start date.
Classification-change exception
The actual period under Article 9(2) and Enforcement Decree Article 5(3) is 45 days.
It runs from a qualifying classification-change amendment or receipt of the customs payment notice based on a different classification.
The statutory delegation ceiling of three months is not the operative filing period.
This exception excludes importers who already claimed preference under Article 8 or Article 9(1).
A price-only amendment or an arbitrary HS change does not automatically qualify.
Both the qualifying classification event and absence of previous preference claims must be verified before the calculator provides a filing-method decision for this route.
If the ordinary period has passed, check applicable exceptions with customs before concluding that no claim is available.
Why the base and reviewed deadlines are separate
The base calculation excludes the initial day and applies calendar periods under Customs Act Article 8 and Civil Act Articles 157 and 160.
Saturdays, Sundays, public and substitute holidays, Labor Day, system outages and special extensions can affect the actual deadline.
The calculator does not assume a complete holiday calendar or knowledge of individual extensions, so its base date excludes those adjustments.
Fictional date checks
- Acceptance 2026-07-15: ordinary base deadline 2027-07-15; review on 2026-10-27: 261 days remaining
- Exception event 2026-10-01: 45-day base deadline 2026-11-15 falls on Sunday
- If customs confirms 2026-11-16, enter that adjusted deadline and confirm the deadline check
- The reviewed deadline itself has zero days remaining; the next day exceeds that reviewed deadline
Leave the adjusted field blank if the verified deadline equals the base date, then confirm the deadline check.
A negative day count alone does not establish lateness before verification.
For release before declaration acceptance, a deemed start date may apply: use the date confirmed with customs.
The review date is the date on which you assess an application, not an expected bank payment date.
Align inputs with the declaration and evidence
Value and rate
Use the declared KRW customs value rather than the shopping checkout price.
Record the agreement, HS code, rate applicable at import and official source.
Purchasing in an agreement partner country does not establish originating status or guarantee a zero rate.
Paid taxes and previous refunds
Separate duty paid, import VAT paid, previous duty refunds and previous VAT refunds.
For a portion of a declaration, use verified attributable amounts.
A simple price-ratio allocation or adding a refund already received can overstate recovery.
Review one declaration portion with one rate at a time.
Calculate different declarations or rates separately and label the saved reviews.
Supported ad valorem rates are 0–100% with up to four decimals.
Specific duties, compound duties and rates above 100% require separate review.
Currency inputs use whole KRW; time inputs allow two decimal places.
Duty differences and previous refunds
Core formulas
- New duty = customs value × verified preferential rate / 100, truncating amounts below KRW 10
- Total duty difference = paid duty − new duty
- Remaining duty refund scenario = positive total duty difference − previous duty refunds
- Remaining VAT adjustment = total VAT adjustment − previous VAT refunds
- Cash recovery scenario = remaining duty refund + remaining VAT adjustment
The ad valorem scenario truncates tax below KRW 10 with reference to National Treasury Funds Management Act Article 47.
Reconcile the final correction against declaration-level tax rounding and customs review.
If new duty exceeds paid duty, the increase is shown separately and the refund comparison is held.
The increase is not a negative refund or an assessed additional payment.
Previous refunds above the total difference produce an input error rather than a misleading remaining refund.
Import VAT cash adjustment and retained benefit
VAT Act Article 29(2) includes duty in the import VAT base; Article 30 sets the 10% rate.
When only duty changes and there are no other linked taxes, new VAT = (customs value + new duty) × 10%, truncated below KRW 10.
Total VAT adjustment = paid VAT − new VAT.
Recomputing the new base matters because simply taking 10% of the duty difference can miss KRW 10 at rounding boundaries.
Paid VAT must also match the original standard VAT base.
If individual consumption tax, liquor tax, education tax or other amounts change, or partial exemptions apply, use the customs-confirmed total adjustment instead.
Final consumer burden
A verified final consumer with no input-credit reversal can enter 0%.
Remaining VAT then contributes to benefit before filing costs.
Choose the excluded method when VAT is exempt or outside the calculation.
Business input-credit adjustment
Enter 100% if the full refunded VAT requires reversal of input credit.
The VAT still appears in clearance cash recovery but contributes nothing to retained benefit.
For partial reversal, use the share verified with your tax adviser.
Retained benefit = remaining duty + remaining VAT × (1 − credit reversal share / 100), truncating retained VAT below KRW 1.
Check corrected import tax invoices under Article 35 and input-credit reporting under Article 38 separately.
The share is a user-confirmed assumption, not an automatic determination of credit eligibility.
The model does not schedule the cash effects of tax-return adjustments.
Compare direct and agent net cash and net benefit
Use consistent cost assumptions
Direct filing includes additional certificate, translation, postage or travel costs and your time.
Agent filing separates the quoted agent fee, other document costs and your remaining time.
Compare additional future costs caused by the choice, rather than sunk past spending.
- Net cash = cash recovery − additional cash cost for that method
- Time cost = additional hours × your hourly value, truncating below KRW 1
- Net benefit = retained benefit − additional cash cost − time cost
- Break-even agent fee ceiling = retained benefit − other agent-route costs − agent-route time cost, displayed as zero if negative
When a nonnegative fee ceiling is reached, net benefit is zero; a lower fee is needed for positive benefit.
If other costs exceed benefit even at a zero fee, the shortfall is shown separately.
If neither method has positive net benefit, review the costs and assumptions.
That economic comparison does not determine legal rights or filing obligations.
Treat recoverable VAT on filing costs consistently for both methods.
Worked example: KRW 800,000 paid duty
This is a fictional calculation check, not an agreement rate or market agent quote.
Assume customs value KRW 10,000,000, paid duty KRW 800,000, paid VAT KRW 1,080,000, a verified 0% preferential rate, no previous refunds and standard VAT.
Remaining duty is KRW 800,000, remaining VAT is KRW 80,000 and cash recovery is KRW 880,000.
Fictional consumer direct and agent filing comparison, KRW| Item | Direct | Agent |
|---|
| Additional cash cost | 20,000 | 100,000 |
| Time × hourly value | 2 h × 20,000 | 0.5 h × 20,000 |
| Net cash | 860,000 | 780,000 |
| Net benefit, no credit reversal | 820,000 | 770,000 |
| Net benefit, full VAT credit reversal | 740,000 | 690,000 |
Without credit reversal, the difference between the two methods is KRW 50,000.
At a 2% preferential rate with the same customs value, new duty is KRW 200,000, total duty difference KRW 600,000 and total VAT adjustment KRW 60,000.
Previous duty and VAT refunds of KRW 100,000 and KRW 10,000 reduce the remaining amounts to KRW 500,000 and KRW 50,000.
VAT is calculated from the total duty difference before previous duty refunds, then previous VAT refunds are deducted independently.
Step-by-step evidence checklist
- Read acceptance, value, paid taxes and the single-rate portion from the declaration.
- Verify the agreement, HS, official import-date rate, origin rule, transport conditions and issuer authority.
- Check certificate validity and excluded periods under Decree Article 5(2).
- Confirm the ordinary or exceptional route, start date and actual deadline after holidays and extensions.
- Reconcile previous refunds and credit reversal, then obtain direct and agent cost quotes.
- Prepare the review, preference application, correction claim and valid evidence, then verify actual submission.
Article 9(5) requires notification of the preference and correction decision within two months after customs receives the correction claim.
This is not a guaranteed payment date and is not used to calculate refund interest here.
Additional evidence requests, actual refund processing and offsets against other taxes require separate confirmation.
Frequently asked questions
Does receiving a certificate guarantee a refund?
No.
Confirm validity, agreement-specific origin, transport and issuer requirements, the rate and filing deadline.
Customs reviews the application.
Does the ordinary clock start when the certificate arrives?
The ordinary period is one year from import declaration acceptance.
Late delivery of a certificate does not by itself restart that period.
Is a claim always lost after one year?
Check qualifying classification-change exceptions and individual conditions.
The 45-day exception runs from the qualifying amendment or payment notice receipt, and previous preference claims matter.
Is VAT always 10% of the duty refund?
Rounding means it may differ.
Standard VAT is recomputed from the new base and subtracted from paid VAT.
For linked taxes or exemptions, enter the verified total adjustment.
Deduct previous VAT refunds separately.
Is refunded VAT all profit for a business?
Any required input-credit reversal reduces retained benefit.
Enter 100% for full reversal and check corrected import invoices and tax reporting.
Are holiday extensions automatic?
The displayed base date excludes holidays.
Verify the actual deadline and enter the adjustment if needed.
The calculator does not establish lateness while that check remains unverified.
Should I always file if the fee is below the ceiling?
The ceiling is an economic scenario based on your cash costs, time value and VAT assumptions.
Verify eligibility and the deadline before checking quotes and preparing the documents.
Can I combine this with a returned-import refund?
Returned-import refunds concern a separate return event and its conditions.
Do not recover the same tax twice.
Reflect previous refunds and confirm the claim route with customs.
Official 2026 sources and update requirements
Sources checked 2026-10-27 using current-law search and article calls to the Korean legislation OPEN API.
FTA Customs Act MST276141: 2026-01-02 edition, Article 9 effective 2025-10-01.
Decree MST282485: 2026-05-01 edition, Article 5 effective 2026-01-06.
Customs Act MST290673: 2026-10-02; VAT Act MST276117 and National Treasury Funds Management Act MST276079: 2026-01-02; Civil Act MST284415: 2026-03-17.
Recheck filing periods, origin evidence validity and import-date HS rates when law or agreements change.
The calculator does not classify HS codes, authenticate origin, determine another country’s deadlines, calculate refund interest, offsets or income-tax effects, or predict payment dates.
Checked boxes record user verification rather than customs approval.
Verify the deadline and costs, then prepare the application
Enter verified declaration values and resolve pending checks first.
Save the comparison and discuss actual submission and evidence with customs or a customs broker.
For goods being returned or manufacturing origin calculations, use the relevant tool to review those separate conditions.