What Is the Tender Offer Rule in Taiwan, 20% Trigger, 20–50 Day Period, Proof-of-funds and Acting-in-concert Rules

Understanding what is the tender offer rule in Taiwan is essential for any acquirer, domestic or foreign, planning a significant stake purchase in a publicly listed Taiwanese company. Governed primarily by the Securities and Exchange Act (SEAct) and the Regulations Governing Public Tender Offers for Securities of Public Companies issued by the Financial Supervisory Commission (FSC), the regime mandates that any acquisition resulting in ownership of 20 per cent or more of a target’s outstanding shares must proceed through a formal public tender offer. The 2024 amendments to these rules tightened proof-of-funds documentation and appraisal requirements, making the compliance landscape more demanding heading into 2025–2026.

This guide walks cross-border deal teams through every critical element: statutory triggers, the 20–50 day offer window, acceptable financing evidence, acting-in-concert aggregation risks, and the filings needed to close a compliant transaction.

Quick Summary, What the Tender Offer Rule in Taiwan Means for Acquirers

Before diving into procedural detail, deal teams should anchor their planning around four pillars of the Taiwan takeover rules. Each one carries specific documentary and timing obligations that, if missed, can derail a transaction or trigger enforcement action by the FSC.

• 20 per cent mandatory trigger. Any person whose aggregate shareholding in a TWSE- or TPEx-listed company will reach or exceed 20 per cent of total issued shares following an acquisition must conduct the purchase through a public tender offer. The threshold is calculated on a fully diluted basis and includes shares held by persons acting in concert with the acquirer, per the Regulations Governing Public Tender Offers for Securities of Public Companies.
• 20–50 day offer period. The tender offer period shall not be less than 20 days nor more than 50 days from the date the public announcement is made. Extensions are required in specific situations, including competing offers and certain regulatory review scenarios.
• Proof-of-funds documentation. The FSC requires that offerors submit credible evidence of their financial capacity at the time of filing. Following the 2024 amendments, the evidentiary standards have been raised, particularly where non-cash consideration is involved, requiring independent appraisals and clearer disclosure of financing structures.
• Acting-in-concert aggregation. Holdings of all parties deemed to be acting in concert with the acquirer are aggregated for purposes of the 20 per cent threshold calculation. The FSC applies a broad, substance-over-form test, and failure to disclose concert-party arrangements can result in administrative penalties or criminal sanctions under the SEAct.

Industry observers expect the FSC to maintain heightened scrutiny of tender offer filings throughout 2025–2026, particularly on proof-of-funds adequacy and concert-party identification. The practical effect is that acquirers must begin assembling financing evidence and mapping related-party arrangements well before any public announcement.

Legal Framework and Statutory Triggers for a Public Tender Offer in Taiwan

The obligation to conduct a public tender offer in Taiwan arises from Article 43-1 of the Securities and Exchange Act. This article establishes the core principle: when any person intends to acquire, either individually or jointly with others, shares of a public company through means other than centralized exchange or over-the-counter trading, and such acquisition would result in the person holding a specified percentage of the company’s total issued shares, the acquisition must be conducted via a public tender offer.

The FSC, acting under authority delegated by the SEAct, promulgated the Regulations Governing Public Tender Offers for Securities of Public Companies. These regulations set the specific ownership threshold at 20 per cent. The calculation includes shares the acquirer already owns, shares to be acquired in the proposed transaction, and shares held by any person acting in concert with the acquirer.

Mandatory versus Voluntary Tender Offers

The securities and exchange act Taiwan tender offer framework distinguishes between mandatory and voluntary offers. A mandatory tender offer is triggered when the 20 per cent threshold is met. A voluntary tender offer may be launched by any person who wishes to acquire shares of a public company through a public solicitation, even if the post-acquisition holding would remain below 20 per cent. Voluntary offers are subject to the same procedural rules, filing, disclosure, offer-period requirements, and settlement obligations, but the acquirer retains more flexibility on conditions and pricing.

Critically, the 20 per cent threshold is not a one-time test. Each subsequent acquisition that, combined with existing holdings, would cause the acquirer (together with concert parties) to cross the threshold triggers the mandatory tender offer requirement afresh. Acquirers who are already above 20 per cent and wish to increase their stake by more than a prescribed percentage within a defined period may also need to conduct a fresh tender offer, depending on the pace and volume of accumulation.

Who Is Eligible to Make a Tender Offer, Offeror and Security Requirements

Under the tender offer requirements in Taiwan, any natural person, juridical person, or other entity, including foreign investors, may serve as an offeror, provided they satisfy the FSC’s disclosure and financial capacity requirements. There is no restriction that limits the tender offer mechanism to domestic acquirers; cross-border private equity funds, strategic corporates, and sovereign wealth funds routinely use this channel.

Domestic versus Foreign Offerors

Foreign offerors face the same tender-offer procedural obligations as domestic acquirers but must additionally comply with Taiwan’s foreign investment regulations. Depending on the industry sector of the target company, approval from the Investment Commission under the Ministry of Economic Affairs (MOEA) may be required before or concurrently with the tender offer filing. Restricted or prohibited industry sectors carry additional screening requirements, and certain investments by mainland Chinese entities are subject to separate, more stringent review.

The securities eligible for tender offers include common shares, preferred shares, and other equity securities listed or traded on the TWSE or TPEx. Convertible bonds and other derivative equity securities may also fall within scope if their conversion or exercise would result in the acquirer crossing the 20 per cent threshold. Nominee and trustee holdings are looked through: the FSC considers the beneficial owner, not the registered holder, when computing aggregate ownership.

Insiders, directors, supervisors, and managerial officers, are not barred from launching a tender offer, but they face heightened disclosure obligations regarding conflicts of interest and must comply with insider-trading restrictions throughout the offer period. A management buyout structured as a tender offer, for instance, triggers additional requirements for board committee review and fairness opinions to protect minority shareholders.

The Tender Offer Period, 20 to 50 Days: Mechanics and Timeline Scenarios

One of the most frequently asked questions about the public tender offer in Taiwan is: what is the minimum time for a tender offer? The Regulations Governing Public Tender Offers answer this directly: the offer period shall not be less than 20 days nor more than 50 days, measured from the date the public announcement is made. The offeror specifies the exact duration within this band in the tender offer filing.

Standard Timeline, Extensions, and Competing Offers

In a straightforward transaction with no competing bids or regulatory complications, most offerors set the period at or near the 20-day minimum to reduce market uncertainty and limit the window for competing offers. However, several circumstances can extend the offer period beyond the originally announced close date. If a competing tender offer is announced during an existing offer period, the original offeror must extend its offer so that at least 10 days remain from the date of the competing announcement. The FSC may also require extensions where it determines that shareholders need additional time to evaluate revised terms or new material information.

The offeror may voluntarily extend the offer period, provided the total does not exceed 50 days. Early termination is generally not permitted, the offer must remain open for the full announced period, giving shareholders a guaranteed window to tender their shares.

Deal teams should model multiple scenarios during the planning phase, factoring in the possibility of a competing bid or a regulatory query that triggers an extension. Early indications suggest that the FSC has been more willing in recent enforcement cycles to order supplementary disclosure, which can effectively lengthen the timeline.

Proof-of-Funds and Financing Disclosure, Current Requirements after the 2024 Amendments

The FSC tender offer proof of funds requirement is one of the most heavily scrutinised elements of a filing. The offeror must demonstrate, at the time it files the tender offer with the FSC and makes the public announcement, that it possesses adequate financial resources to complete the acquisition at the offered price for the maximum number of shares sought.

What the FSC Expects: Acceptable Documentation

The 2024 amendments to the Regulations Governing Public Tender Offers strengthened the evidentiary standards for proof of funds. Where cash consideration is offered, the FSC expects one or more of the following forms of evidence. Where non-cash consideration (such as shares of the acquirer) is offered, independent appraisals are now mandatory.

For cross-border acquirers, additional practical hurdles apply. Financing documents issued in a foreign language typically must be accompanied by certified Mandarin translations. Where funds are held offshore, the offeror should demonstrate the ability to remit and convert currency into New Taiwan Dollars within the offer settlement timeline. The likely practical effect of the 2024 amendments is that foreign bidders now need to engage Taiwanese banking and appraisal professionals earlier in the deal process, ideally before the formal filing, to ensure documentation meets the FSC’s heightened standards.

Acting-in-Concert Rules in Taiwan, Definition, Examples, and Enforcement Risks

The acting in concert Taiwan rules represent one of the most consequential, and least intuitive, compliance traps in Taiwanese public M&A. Under the FSC’s regulations, parties are considered to be acting in concert if they have an agreement, arrangement, or understanding, whether written or unwritten, to coordinate the acquisition, holding, or exercise of voting rights in a public company’s shares.

How Aggregate Holdings Are Computed and Common Triggers

The FSC aggregates the holdings of all concert parties for purposes of the 20 per cent mandatory tender offer threshold. This means that two investors, each holding 12 per cent, would collectively be treated as holding 24 per cent and would be required to have acquired their stakes via a tender offer. The test is substance-over-form: the FSC examines the actual relationship and pattern of behaviour, not merely formal agreements.

The following checklist highlights common red flags that may lead the FSC to treat parties as acting in concert:

• Joint acquisition planning. Sharing acquisition strategies, target-price thresholds, or timing coordination, even informally, between two or more investors.
• Common financing arrangements. One party funding or guaranteeing another’s share purchases in the same target company.
• Board nomination agreements. Arrangements to jointly nominate directors or supervisors, or to vote in a coordinated manner at shareholder meetings.
• Family and corporate affiliations. Related individuals (spouses, close relatives) or entities under common control that independently accumulate shares.
• Sequential or timed purchases. Patterns of trading activity that, when viewed together, suggest coordinated accumulation rather than independent decision-making.
• Shared advisors or intermediaries. Using the same broker, financial advisor, or legal counsel to execute parallel acquisition strategies in the same target.

Penalties for failing to disclose concert-party arrangements are severe. The FSC may impose administrative fines, require corrective public disclosures, and in cases of deliberate concealment, refer matters for criminal investigation under the SEAct. The reputational and deal-execution costs of an enforcement action often dwarf the monetary penalties.

Mandatory Filings, Disclosure Obligations, and Penalties for Non-Compliance

A compliant tender offer in Taiwan requires multiple filings and public disclosures, each governed by strict deadlines. Failure to file accurately and on time can result in the FSC suspending or prohibiting the offer, or imposing post-completion sanctions.

Key Filings and Timelines

The target company’s board of directors has independent obligations: it must publish its own announcement acknowledging the offer, convene to evaluate the terms, and issue a recommendation to shareholders, typically advising whether to accept, reject, or take no position. If the board engages an independent financial advisor or obtains a fairness opinion, that report must also be disclosed.

The penalty regime under the SEAct includes administrative fines for procedural violations, mandatory corrective disclosures, and the power to nullify improperly conducted acquisitions. In cases involving deliberate concealment of material information, insider trading during the offer period, or fraudulent proof-of-funds documentation, criminal liability may attach, including imprisonment and substantial monetary penalties.

Cross-Border Practicalities, Foreign Investment Approval, Tax, and Financing

Foreign acquirers navigating the tender offer rule in Taiwan must layer several additional regulatory requirements on top of the core tender-offer procedure. The most significant is the potential need for approval from the Investment Commission of the MOEA under the Statute for Investment by Foreign Nationals. Whether approval is required, and the level of scrutiny applied, depends on the industry sector of the target company and the nationality of the investor. Investments in restricted sectors (such as telecommunications, broadcasting, and certain technology industries) face heightened review and potential conditions.

From a tax perspective, foreign offerors should consider the withholding tax implications on any premium paid, the securities transaction tax levied on share transfers on the TWSE, and the potential application of double-taxation treaties between Taiwan and the offeror’s home jurisdiction. Currency controls are relatively light in Taiwan, but large cross-border remittances require advance reporting to the Central Bank of the Republic of China (Taiwan). Deal teams should ensure that foreign-currency-denominated financing can be converted and settled in New Taiwan Dollars within the tight post-offer settlement window.

Given the interaction between securities law, foreign investment regulations, and tax rules, early engagement of local Taiwanese legal and tax counsel is strongly recommended for any cross-border tender offer.

Practical Checklist and Sample Timeline for a Voluntary Tender Offer

The following checklist outlines the core steps for a voluntary public tender offer in Taiwan, from pre-launch preparation through final settlement. Timelines will vary based on deal complexity and whether foreign investment approvals are needed.

• Pre-launch (T-60 to T-30 days). Engage local counsel, financial advisor, and mandated agent. Begin assembling proof-of-funds documentation. Map concert-party relationships and confirm aggregate holdings. Assess foreign investment approval requirements.
• Documentation (T-30 to T-7 days). Prepare tender offer filing, shareholder circular, and public announcement materials. Obtain financing commitments and bank confirmations. Arrange independent appraisals if non-cash consideration is contemplated.
• Filing and launch (T-day). Submit tender offer registration to the FSC. Make simultaneous public announcement on TWSE/TPEx. Deliver shareholder circular.
• Offer period (T-day to T+20 minimum, T+50 maximum). Monitor for competing bids; manage extensions if triggered. Respond to FSC queries on proof of funds or disclosure. Target board issues recommendation.
• Close and settlement (T+20/50 to T+settlement deadline). Tabulate tendered shares. Complete payment through mandated agent. File post-completion reports with the FSC and TWSE. Update share capital records and beneficial ownership registers as required.

Conclusion, Key Takeaways on the Tender Offer Rule in Taiwan

The Taiwan tender offer rules form a tightly regulated framework designed to protect minority shareholders while providing a clear pathway for legitimate acquisitions of public companies. The 20 per cent mandatory threshold, the 20–50 day offer period, the strengthened proof-of-funds requirements introduced by the 2024 amendments, and the broad acting-in-concert aggregation rules collectively demand early planning, robust documentation, and meticulous regulatory engagement from any acquirer.

For cross-border deal teams, the additional layers of foreign investment approval, tax structuring, and currency conversion make expert local guidance indispensable. Understanding what is the tender offer rule in Taiwan at a granular level, and building that understanding into the deal timeline from day one, is the single most effective way to avoid enforcement risk and deliver a successful acquisition. Disclosure letters remain a critical companion document in any M&A transaction; practitioners can review why disclosure letters are crucial in M&A deals for additional context on seller-side disclosure obligations that frequently intersect with tender offer processes.

Sources

1. Financial Supervisory Commission, Regulations Governing Public Tender Offers (English)
2. Securities and Exchange Act (Taiwan), Official Text
3. Taiwan Stock Exchange, Rules and Regulations (Tender Offer / Consideration)
4. Baker McKenzie, Effecting a Takeover (Taiwan)
5. Lee and Li, Amendments to the Tender Offer Rules (2024)
6. NTU Law Center, Academic Article on Tender Offer Regulations
7. Lexology, Legal Framework for Public M&A in Taiwan