Step‑by‑step Guide to Merger Notification & Clearance in South Korea

Any company completing an acquisition, merger or share purchase that meets the statutory thresholds under South Korea’s Monopoly Regulation and Fair Trade Act (MRFTA) must follow the merger notification procedure in South Korea administered by the Korea Fair Trade Commission (KFTC). The obligation extends to foreign acquirers whose transactions produce an effect on the Korean market, making the process a standing concern for cross‑border private equity, corporate development and strategic buyers alike. With the KFTC having published updated administrative guidance and refined its simplified‑review and pre‑filing consultation practices in late 2025 and early 2026, transaction teams now face both new opportunities to accelerate clearance and new expectations regarding submission format and economic evidence.

This guide walks through each stage of the merger clearance process, from threshold screening to final decision, with the timelines, document checklists and practical tips that in‑house counsel need to plan a filing with confidence.

Overview of the Merger Notification Procedure in South Korea

South Korea operates a mandatory, post‑closing merger notification regime. The statutory framework sits in the MRFTA, which empowers the KFTC to review combinations that may substantially lessen competition. The types of transactions caught include share acquisitions (where the acquirer’s shareholding crosses prescribed percentage thresholds), mergers and consolidations, business or asset transfers, formation of new joint ventures, and interlocking directorates.

The core filing obligation is straightforward: parties that satisfy the turnover and asset thresholds must notify the KFTC within 30 calendar days of consummation. For most share deals, “consummation” means the date the shares are transferred on the register; for statutory mergers, it is the date the merger becomes effective under commercial law. A limited category of large‑scale transactions requires pre‑closing notification, meaning the filing must be made before the deal closes and the parties must wait for clearance before completing the combination.

The KFTC then conducts a phased review. Most routine filings are cleared within 30 calendar days. Transactions that qualify for the KFTC’s simplified review practice may be cleared in approximately 15 calendar days. Complex cases can be extended by up to 90 additional days, yielding a maximum statutory review window of 120 calendar days. Understanding which track your transaction is likely to follow, and preparing the economic evidence accordingly, is the single most important planning decision in any Korean merger filing.

Merger Control Requirements in South Korea: Eligibility and Prerequisites

Not every M&A transaction triggers a KFTC filing. The MRFTA sets dual thresholds, one for the acquiring entity (or its group) and one for the target, based on total assets or annual turnover. Both thresholds must be met simultaneously for the notification obligation to arise.

Filing Threshold Overview

These thresholds are calculated on a worldwide, group‑wide basis, which means a foreign buyer’s global revenue counts toward the acquirer threshold. The target threshold is assessed using the Korean target’s figures (or, for an overseas target, revenue attributable to Korea where the transaction affects the domestic market). Industry observers expect the KFTC to continue adjusting these thresholds periodically in line with inflation and market developments, so teams should verify the current levels at the time of filing.

Who Must File, Domestic and Foreign Acquirers

Domestic acquirers file whenever the dual thresholds are met. Foreign acquirers face an additional analytical step: confirming that the transaction has an effect on the Korean market. In practice, this nexus test is satisfied where the target (or the acquirer) has sales into Korea, maintains Korean subsidiaries, or holds intellectual property licensed to Korean customers. A foreign‑to‑foreign deal with no Korean nexus does not trigger notification, but the burden of establishing that absence falls on the parties.

Before filing, transaction teams should ensure the following prerequisites are in place:

• Board resolutions or equivalent corporate authority. The KFTC expects evidence that the filing party has the authority to pursue the transaction. Provide certified board minutes or shareholder resolutions.
• Executed or substantially final transaction agreements. The notification form requires details of the deal terms, consideration and conditions precedent.
• Preliminary market‑share analysis. Even at threshold‑screening stage, teams should run initial market‑share calculations to gauge whether simplified review is likely or whether an in‑depth economic study will be needed.
• Korean legal counsel and power of attorney. Foreign filers must appoint Korean counsel authorised to communicate with the KFTC on their behalf.

The 30‑day filing deadline runs from consummation, not from signing. This distinction is critical: if a share purchase agreement is signed on 1 March but shares transfer on 20 March, the deadline expires on 19 April. Miscounting this date is one of the most common procedural errors in Korean merger filings.

Step‑by‑Step Merger Notification Procedure in South Korea

The following numbered procedure covers every stage from initial screening through to final clearance or, in rare cases, prohibition. The accompanying timeline table summarises who does what and how long each step typically takes.

Step 1: Pre‑Deal Screening and Internal Threshold Check

Before any engagement with the KFTC, the acquirer’s legal team must determine whether the filing threshold is met. This involves consolidating worldwide group revenue (or total assets) for the acquiring group and verifying the target’s figures against the applicable threshold. For foreign deals, the analysis should also confirm Korean nexus, evidence of sales into Korea, Korean employees, assets, or licensed IP.

At this stage, the competition economist should prepare a preliminary market definition and market‑share estimate. If the combined market share in any plausible product or geographic market exceeds the KFTC’s safe‑harbour thresholds, the team should plan for a full economic submission. If combined shares are modest, typically below the levels that the KFTC treats as presumptively unproblematic, the transaction may qualify for simplified review, and the filing can be prepared in a more streamlined format.

Step 2: Pre‑Filing Consultation with the KFTC

The KFTC offers an informal pre‑filing consultation channel that, while optional, is strongly recommended for complex or cross‑border transactions. Early indications from KFTC practice in 2025–2026 suggest that the regulator is encouraging greater use of this mechanism to reduce deficiency queries after formal submission.

To initiate a consultation, Korean counsel typically contacts the KFTC’s Merger Division, either through the designated email channel or by written letter, describing the transaction structure, the parties, the affected markets, and any preliminary competition concerns. The consultation is not binding on either side, but it enables the KFTC to signal whether simplified review is likely, flag data it will require, and identify potential substantive issues early. Allow two to four weeks for the KFTC to respond, though response times vary with case complexity and the Commission’s workload.

The practical benefit of pre‑filing consultation is twofold. First, it reduces the risk of the KFTC issuing information requests after formal filing (which effectively pauses the review clock). Second, it allows deal teams to prepare tailored economic evidence, avoiding both over‑ and under‑preparation.

Step 3: Preparing and Submitting the Formal Notification

The formal filing is made using the KFTC’s prescribed notification form, a standardised template that the Commission updated in its latest administrative guidance. Korean counsel should download the most recent version from the KFTC’s website and complete all mandatory fields. The form requires:

• Identification of the parties (acquirer, target, and any intermediate holding entities).
• A description of the transaction, including structure, consideration and conditions precedent.
• The date of consummation (or, for pre‑closing filings, the anticipated consummation date).
• Market‑share data, relevant market definitions, and an assessment of competitive effects.
• A list of all supporting documents (see the Required Documents section below).

The completed notification, with supporting documents, is submitted to the KFTC. All filings in Korean are standard; foreign‑language documents require certified Korean translations. The filing date, Day 0 for the review clock, is the date the KFTC acknowledges receipt of a complete submission. If the submission is incomplete, the KFTC will issue a deficiency notice and the clock does not start until the deficiency is cured.

Step 4: KFTC First‑Phase Review, Standard and Simplified Tracks

Once the filing is accepted as complete, the KFTC begins its first‑phase review. For a standard review, the KFTC has 30 calendar days from the filing date to reach a decision. During this period, the KFTC may issue information requests, formal written demands for additional data, market studies, customer contracts, or internal strategy documents. Prompt, comprehensive responses to these requests are critical; delays can effectively extend the review window.

Transactions that satisfy the KFTC’s simplified review criteria, generally those where the parties’ combined market shares in all affected markets remain below prescribed levels and no vertical or conglomerate concerns arise, may be cleared in approximately 15 calendar days. The simplified review track reflects the KFTC’s practice of fast‑tracking straightforward combinations. It is not a separate statutory procedure but rather an internal administrative commitment to expedite review where substantive concerns are minimal.

At the conclusion of the first phase, the KFTC will either clear the transaction (unconditionally or with conditions), indicate that it intends to extend review into a second phase, or, in rare cases, open a formal investigation.

Step 5: Extended Review, Remedies, Conditional Clearance or Prohibition

If the KFTC determines that the transaction raises substantive competition concerns that cannot be resolved within 30 days, it may extend the review by up to 90 additional calendar days, giving a total review window of up to 120 days. Extended reviews are typically reserved for horizontal mergers in concentrated markets, vertical integrations with foreclosure potential, or transactions involving novel market definitions.

During extended review, the KFTC engages with the parties on potential KFTC remedies and undertakings, structural (divestiture of business units or assets) or behavioural (commitments on pricing, access, or supply). The parties may propose remedies proactively or respond to the KFTC’s draft conditions. Remedy negotiations can take several weeks and often require additional economic modelling.

Prohibition is uncommon but not without precedent. If the KFTC concludes that the transaction will substantially lessen competition and no adequate remedy is available, it may block the deal. The parties have the right to appeal a prohibition decision to the Seoul High Court.

Documents Needed for Merger Notification in South Korea

The KFTC expects a comprehensive filing package. The documents below are divided into legal and transactional materials and economic evidence. Preparing a complete package at the outset reduces the risk of deficiency notices and information requests that pause the review clock.

In practice, the KFTC most frequently issues information requests for market‑share evidence, customer lists, internal strategy documents, and closing/consummation evidence. Transaction teams that assemble these materials proactively, rather than waiting for a formal request, consistently achieve shorter review times.

KFTC Filing Timeline and Key Deadlines

The merger notification procedure in South Korea is governed by strict statutory deadlines. The table below consolidates the key time limits that deal teams must track.

A critical distinction for the KFTC filing timeline is the difference between signing and consummation. “Consummation” under the MRFTA means the legal completion of the transaction, the transfer of shares on the register, the effective date of a statutory merger, or the date assets are delivered. It does not mean the date the parties sign the agreement. For example, if a share purchase agreement is signed on 15 January but the share transfer completes on 10 February, the 30‑day filing deadline expires on 12 March (allowing for the way calendar days are counted). Teams should calculate this date carefully and build a buffer of at least five business days to account for document preparation and Korean counsel coordination.

For large‑scale transactions that require pre‑closing notification, the filing must be submitted before consummation and the parties may not close until clearance is obtained or the review period expires without a decision.

Costs, Fees and Practical Expenses

The direct regulatory cost of filing a merger notification in South Korea is modest compared to many other jurisdictions. The table below outlines the main cost categories.

The largest variable cost is typically the competition economist’s fee. For transactions with multiple overlapping markets, detailed quantitative analysis (including merger simulation or upward pricing pressure calculations) can significantly increase the economic evidence budget. Early engagement with the economist, ideally during the pre‑filing consultation stage, helps control costs by focusing the analysis on the markets the KFTC is most likely to scrutinise.

What Changed in 2025–2026: KFTC Administrative and Practice Updates

Several administrative developments in late 2025 and early 2026 have refined the practical steps of the merger notification procedure in South Korea:

• Updated notification templates and guidance. The KFTC circulated revised notification form templates with standardised fields for market definition, competitive‑effects analysis and remedies proposals. The likely practical effect is greater consistency in filings and fewer deficiency notices, provided teams use the latest template version.
• Refined simplified‑review criteria. The KFTC has clarified the eligibility criteria for simplified review, reinforcing its commitment to clearing straightforward transactions within approximately 15 calendar days. Industry observers expect this to benefit foreign‑to‑foreign deals with limited Korean overlap and transactions in fragmented markets.
• Enhanced pre‑filing consultation practice. The KFTC has encouraged earlier and more structured pre‑filing engagement, including through its designated communication channels. Early indications suggest that pre‑filing consultations are producing more specific KFTC feedback on data expectations, reducing the incidence of formal information requests during the review phase.
• Alignment with broader MRFTA amendments. Recent MRFTA amendments affecting merger control, including adjustments to the calculation of thresholds and administrative fine provisions, are now fully in force. Filing teams should confirm that their threshold calculations reflect the current statutory text.

Common Pitfalls in Korean Merger Filings and How to Avoid Them

• Confusing signing with consummation. The 30‑day clock starts at consummation, not at signing. Teams that calculate from the wrong trigger date risk filing late and facing administrative penalties. Build a clear timeline with absolute dates the moment the closing date is set.
• Underestimating the volume of required data. The KFTC’s information requests can be extensive, particularly regarding market‑share calculations, customer lists, and internal strategy documents. Prepare consolidated data schedules during due diligence rather than scrambling after the filing is submitted.
• Skipping pre‑filing consultation on cross‑border deals. Foreign acquirers who proceed directly to formal filing without engaging the KFTC informally often receive deficiency notices that delay the review clock. A pre‑filing consultation is especially valuable for establishing Korean nexus and confirming which track the KFTC is likely to apply.
• Submitting weak economic evidence. Market‑share data without a clearly articulated methodology, or competitive‑effects analysis that relies on unsupported assertions, will prompt KFTC requests for additional information. Retain a competition economist early and ensure the methodology is transparent and defensible.
• Closing before clearance without contractual protections. While most Korean merger notifications are filed post‑closing, parties must not close a transaction that requires pre‑closing notification until clearance is obtained. Even for post‑closing filings, closing before the KFTC issues its decision carries enforcement risk if the KFTC subsequently imposes conditions or structural remedies. Include appropriate indemnities and hold‑separate obligations in the transaction agreements.

Sources

1. Korea Fair Trade Commission (KFTC), English pages and guidance
2. Kim & Chang, Implementation of Amended Merger Control Administrative Guidance
3. ICLG, Merger Control Laws and Regulations: Korea (2026)
4. Lex Mundi, Merger Notification Guide: Korea
5. International Competition Network (ICN), Korea Merger Template
6. Cornerstone Research, Fundamentals of East Asia Merger Control (2025)
7. Shin & Kim, Merger Control Newsletter
8. Lee & Ko, Recent MRFTA Changes Summary