Belgium 2026: How Code of Economic Law & Civil Code Reforms Change M&A, Business Transfers & Shareholder Agreements

Last reviewed: 18 May 2026

The landscape of M&A law in Belgium shifted materially on 1 January 2026, when long-awaited reforms to Book 3 of the Civil Code, covering personal security rights and guarantees, came into force alongside a package of amendments to the Code of Economic Law adopted earlier that month. Together, these changes rewrite the rules that govern how buyers take security, how sellers give guarantees, and how shareholder agreements are enforced in every business transfer in Belgium. For corporate counsel, SME owners, family businesses and lenders negotiating or closing transactions in 2026, the immediate question is whether to proceed under existing deal documentation, renegotiate key terms, or delay closing until new-format security packages are in place.

This guide answers that question with practical checklists, sample clause language and a step-by-step timeline that any party to a Belgian deal can act on today.

Key Changes: What the Code of Economic Law Amendments Mean for M&A Law in Belgium

The January 2026 amendments to the Code of Economic Law (Wetboek van economisch recht / Code de droit économique) targeted several provisions that directly affect transaction structure, pre-contractual information obligations and regulatory compliance in mergers and acquisitions in Belgium. Published in the Moniteur belge, the reforms update rules on pre-contractual disclosure, unfair market practices between enterprises, and the competition notification framework.

What the Code Amendments Change for Transaction Structure

• Enhanced pre-contractual information duties. Sellers in asset deals and business transfers must now provide broader mandatory disclosures to prospective buyers before a binding agreement is formed. This increases the scope and detail of information that must be assembled during early-stage due diligence.
• Revised unfair-market-practices provisions. The amendments tighten the rules on what constitutes unfair contractual terms in B2B relationships, which means that heavily one-sided warranty or indemnity clauses between commercial parties face greater enforceability risk.
• Competition notification adjustments. Thresholds and procedural steps for notifying the Belgian Competition Authority (Belgische Mededingingsautoriteit / Autorité belge de la Concurrence) have been recalibrated. Parties to mid-market transactions should verify whether their deal now falls within the revised notification thresholds before signing.
• Digital and data-related compliance. New provisions address the transfer of digital assets, customer databases and data-processing agreements within the scope of a business transfer, requiring explicit contractual treatment in the sale documentation.

Who Is Affected: Buyer, Seller, Guarantor and Third-Party Lenders

The code of economic law Belgium reforms do not only affect principals. Any party providing or benefiting from a personal guarantee, any lender holding security over business assets, and any third-party counterpart whose consent is needed for contract novation must reassess existing documentation. Industry observers expect the Belgian Competition Authority to publish detailed guidance on the revised notification thresholds by mid-2026, but parties should not wait for that guidance before adjusting deal timetables.

Key takeaway: If your transaction involves Belgian-law warranties, indemnities or B2B supply contracts, verify compliance with the amended Code of Economic Law before exchanging binding commitments.

Civil Code Reforms Belgium: Guarantees & Security Rights (Effective 1 January 2026)

The reform of Book 3 of the Belgian Civil Code, covering personal security, suretyship (borgstelling / cautionnement) and independent guarantees, is the single most consequential change for deal documentation in 2026. These civil code reforms in Belgium replace the Napoleonic-era rules on suretyship with a modern, codified regime that introduces stricter formal requirements, clearer enforceability rules and an updated priority framework for competing security interests.

What Changed: Formalities, Enforceability and Priority

• Mandatory written form and content requirements. A personal guarantee (borgstelling) must now be evidenced in a signed written instrument that explicitly states the maximum guaranteed amount and the duration of the guarantee. Guarantees that omit either element risk being declared unenforceable.
• Proportionality test for natural-person guarantors. Where the guarantor is a natural person (common in family-business M&A), the guarantee must be proportionate to the guarantor’s assets and income at the time of execution. A disproportionate guarantee can be reduced or set aside by a court.
• Information obligations towards the guarantor. The beneficiary of a guarantee (typically the buyer or a lender) must now inform the guarantor annually of the outstanding amount of the guaranteed obligation and any material change in the debtor’s financial position.
• Ranking and priority clarification. The reformed rules establish a clearer statutory ranking between suretyship, independent guarantees and real security rights. This directly affects intercreditor arrangements in leveraged acquisitions.
• Transitional provisions. Guarantees executed before 1 January 2026 remain governed by the former rules, unless the guaranteed obligation is materially novated or the guarantee is amended after that date, in which case the new regime applies in full. Early indications suggest this “novation trigger” will catch more deals than parties initially assumed.

Practical Consequences for Guarantees & Security Rights in Belgium

For guarantees and security rights in Belgium, the practical effect is immediate. Every guarantee clause in a share purchase agreement (SPA), asset purchase agreement (APA) or shareholder agreement must now be reviewed against the new formality checklist. Clauses that previously relied on a simple side letter from a managing director or family member may no longer satisfy the written-form requirements. Similarly, buyers who hold a personal guarantee from the seller’s principal shareholder must ensure the proportionality test is met and the annual information obligation is contractually allocated.

The likely practical effect for leveraged deals will be a restructuring of security packages: lenders are expected to insist on independent bank guarantees or escrow arrangements rather than personal suretyship wherever the guarantor is a natural person.

Key takeaway: Audit every guarantee in your deal documentation. If any guarantee was drafted before 1 January 2026 and the underlying obligation is being novated at closing, the full new Civil Code regime applies.

Asset vs Share Deals & Transfer of Undertakings in Belgium

The choice between an asset deal and a share deal has always been central to any business transfer in Belgium. The 2026 reforms sharpen that distinction by altering the risk profile on both sides.

Employee-Transfer Checklist (Transfer of Undertakings Belgium)

Where a deal qualifies as a transfer of undertakings in Belgium (modelled on the EU Acquired Rights Directive), employees transfer automatically to the buyer. The 2026 reforms do not overhaul the core TUPE framework, but the enhanced pre-contractual information duties under the Code of Economic Law now require additional employee-related disclosures earlier in the process. Buyers should:

• Identify all employees attached to the transferring business unit at least 30 days before signing.
• Request copies of employment contracts, collective bargaining agreements and benefit plans.
• Assess pension and bonus liabilities and confirm whether personal guarantees securing employee obligations comply with new formalities.
• Inform and consult employee representatives in accordance with Belgian social-dialogue requirements.

Due Diligence & Pre-Closing Steps for Belgian M&A in 2026

The combined effect of the Code of Economic Law amendments and the Civil Code reforms creates a longer and more detailed due diligence checklist for mergers and acquisitions in Belgium. Buyers and sellers should work through the following twelve-point framework before closing.

Key takeaway: Begin due diligence with a guarantee audit (item 1) and a security-interest search (item 2). These two steps determine whether the rest of your deal documentation needs restructuring.

Contract Drafting: Warranties, Indemnities, Guarantees, Security & Escrow Under M&A Law Belgium

The 2026 reforms introduce several alarm points for drafters. Warranty and indemnity clauses that were market-standard in 2024–2025 Belgian SPAs may now carry enforceability risk, and guarantee clauses require structural revision to satisfy the new Civil Code formalities. Below are the priority drafting changes and two illustrative sample clauses.

Priority Drafting Changes

• State the maximum guaranteed amount expressly. Every personal guarantee must now include a monetary cap. Open-ended guarantees (e.g., “all obligations of the Seller under this Agreement”) are at risk of nullity.
• Include a duration clause. If the guarantee is for a defined warranty period (e.g., 24 months post-closing), state the expiry date explicitly in the guarantee instrument.
• Address the proportionality test. Where the guarantor is a natural person, include a recital confirming that the guarantee amount is proportionate to the guarantor’s disclosed net worth. Consider attaching a net-worth certificate.
• Allocate the annual information obligation. Specify in the SPA which party (buyer or its agent) bears responsibility for the annual notification to the guarantor and the consequences of non-compliance.
• Review B2B indemnity caps for unfair-terms risk. Ensure indemnity provisions between commercial parties are balanced and do not create a significant imbalance that could be challenged under the revised Code of Economic Law.

Sample Clause: Personal Guarantee (New Formalities)

Note: The following is illustrative only and must be adapted to the specific transaction by qualified Belgian counsel.

Clause [●], Personal Guarantee The Guarantor hereby irrevocably and unconditionally guarantees to the Buyer the due and punctual performance by the Seller of each of the Seller’s Warranty Obligations under this Agreement, up to a maximum aggregate amount of EUR [●] (the “Guaranteed Amount”), for a period expiring on the date falling [24] months after the Closing Date (the “Guarantee Period”). The Guarantor confirms that the Guaranteed Amount is proportionate to the Guarantor’s assets and income, as evidenced by the net-worth certificate attached at Schedule [●].

The Buyer shall, no later than each anniversary of the Closing Date during the Guarantee Period, provide the Guarantor with a written statement of the outstanding amount of any pending Warranty Claims and any material change in the Seller’s financial position of which the Buyer is aware.

Sample Clause: Security Grant and Registration

Note: Illustrative only, seek qualified Belgian counsel before use.

Clause [●], Security Grant

As continuing security for the Seller’s obligations under the Warranty and Indemnity provisions of this Agreement, the Seller hereby grants to the Buyer a first-ranking pledge over the Escrow Account and all amounts standing to the credit thereof.

The Parties shall procure that this pledge is registered with the National Pledge Register (Nationaal Pandregister / Registre national des gages) within [5] Business Days of the Closing Date. The Seller shall bear the costs of registration. Priority of this pledge shall be determined by the date and time of registration in accordance with Book 3 of the Civil Code as reformed with effect from 1 January 2026.

Shareholder Agreements in Belgium: What to Update Now

Do shareholder agreements and buy-sell clauses need to be updated because of the 2026 reforms? The answer is unequivocally yes. Any shareholder agreement in Belgium that contains personal guarantees, security over shares, transfer restrictions triggered by a change in law, or valuation mechanisms referencing statutory provisions requires immediate review. The six priority updates are:

• Transfer mechanics. Review whether the share-transfer procedure references Code of Economic Law provisions that have been amended. Update cross-references and ensure any pre-emption notice periods align with the new pre-contractual disclosure timeline.
• Buy-sell price triggers. If the agreement uses a formula tied to statutory valuation rules or auditor-determined fair value, confirm that the formula remains valid and that any guarantee supporting the price-adjustment mechanism satisfies the new formality requirements.
• Security over shares. Pledges over shares used to secure tag-along, drag-along or call-option obligations must be re-examined against the reformed priority and registration rules. Re-registration may be advisable.
• Guarantee enforcement. Clauses permitting a party to call on a personal guarantee (e.g., to fund a buy-out) must now include the prescribed written-form elements and proportionality confirmation.
• Change-of-control triggers. If the agreement treats a change of law as a trigger event, the 2026 reforms may themselves constitute a triggering event. Review the definition and, if necessary, carve out legislative reforms from the trigger.
• Deadlock resolution. Deadlock provisions that involve forced-sale mechanisms or third-party valuation should be aligned with the revised security and guarantee framework to avoid enforcement gaps. See existing guidance on deadlock provisions in shareholder agreements for background.

For shareholders in closely held or family-owned companies, minority shareholders’ protection is an additional area where the reformed rules may alter the balance of rights. Minority holders should verify whether existing protections remain enforceable.

Post-Signing & Integration Risks: Novation, Security Enforcement and Dispute Resolution

Closing a transaction is only the midpoint. Post-signing, several integration risks arise under the 2026 reforms that require active management:

• Novation awareness. Any post-closing amendment that materially changes the guaranteed obligation will trigger the new Civil Code regime. Before amending supply contracts, financing arrangements or intercompany loans, assess whether the amendment constitutes a novation.
• Security-agent and trustee structures. For syndicated or multi-lender deals, industry observers expect a rapid shift towards trustee or security-agent structures to centralise registration, manage priority and handle enforcement under the reformed framework.
• Escrow release and indemnity protocols. Agree at closing on a detailed escrow-release schedule that accounts for the guarantee period, the annual-information obligation, and the time needed to resolve any pending warranty claims.
• Dispute resolution clause review. Confirm that arbitration or jurisdiction clauses account for the possibility that guarantee disputes may now involve separate formality challenges. Consider including an expedited procedure for formality-validity disputes.

Parties should also review whether any new Belgian criminal-code provisions enacted in 2026 create additional compliance obligations for directors or officers involved in the transaction.

Timeline of Key Legislative Dates

Conclusion: Immediate Action Steps for M&A Law Belgium in 2026

The combined effect of Belgium’s 2026 Code of Economic Law amendments and Civil Code reforms is a structural shift in how transactions are documented, secured and enforced. Buyers, sellers, shareholders and lenders who act quickly, auditing guarantees, updating security packages, revising shareholder agreements and recalibrating due diligence, will close deals with confidence. Those who delay risk unenforceable guarantees, regulatory non-compliance and costly post-closing disputes. For further guidance on international commercial transactions and to connect with qualified Belgian M&A counsel, consult the Global Law Experts lawyer directory.

Sources

1. CMS Belgium, Mergers & Acquisitions
2. KPMG Law Belgium, Corporate and M&A
3. PwC Legal Belgium, Mergers & Acquisitions
4. Belgian Official Gazette / Moniteur belge
5. CMS Belgium
6. Tiberghien