Merger and acquisition are used interchangeably in business conversation, yet they are legally and fiscally distinct operations. The confusion can be expensive: the wrong structure in a corporate reorganisation can produce an unexpected tax charge of several hundred thousand pounds, or operational complications that take years to unwind. This guide explains the differences precisely and, more importantly, tells you when to use each.
For readers familiar with UK or US M&A practice, the Spanish framework will feel broadly recognisable in concept but differs in meaningful ways — particularly in the statutory merger process, the fiscal neutrality regime, and the role of the notary and Registro Mercantil. Those differences are the focus here.
Four Distinct Operations Under the M&A Umbrella
The term M&A groups four legally distinct operation types with different corporate, tax and operational consequences.
Merger by Absorption (Fusión por Absorción)
One company (the absorbing company) incorporates one or more others (the absorbed companies), which are extinguished without liquidation. Shareholders of the absorbed companies receive participations in the absorbing company in a ratio determined by the exchange ratio, calculated from the relative valuations of the participating entities. The absorbing company assumes universally and automatically all rights, obligations and contracts of the absorbed companies.
Merger by absorption is governed by Title II of Ley 3/2009 on Structural Modifications of Commercial Companies (LME). The process requires: an administration body report from each participating company; an independent expert’s report (unless waived by unanimous shareholder vote); a merger plan filed with the Registro Mercantil; extraordinary general meetings with qualified majority approval; and a notarial deed of merger registered in the Registro Mercantil. The realistic minimum timeline from commencement to registration is three months; four to six months is more common.
Merger by Formation of a New Company (Fusión por Constitución)
Two or more companies are simultaneously extinguished and their assets and liabilities transfer to a newly formed company. Shareholders of all participating companies receive participations in the new entity. This structure is less common than merger by absorption because it requires incorporating a new company, with the associated formalities and cost.
Acquisition of Participations (Share Deal)
A company or individual purchases all or part of the participations of another company. The acquired company continues as an independent legal entity: there is no extinction, no universal transfer of assets. Transfer of participations in a Sociedad de Responsabilidad Limitada (SL) requires a public notarial deed; in a Sociedad Anónima (SA), transfer is by endorsement or physical delivery of the share certificate. The target becomes a subsidiary of the buyer.
Acquisition of Assets (Asset Deal)
A company purchases specific assets of another: plant, customer portfolio, brands, premises, selected contracts. The vendor company continues with its remaining assets (and the liabilities not transferred). Each asset requires its own transfer mechanism: notarial deed for real estate, contractual assignment for contracts, registry filing for trademarks and industrial property rights.
8-Dimension Comparison: Merger vs Acquisition
| Dimension | Merger | Acquisition |
|---|---|---|
| Resulting structure | Single entity (absorbing or new) | Group: buyer + subsidiary (or holding + subsidiary) |
| Tax treatment | Deferred fiscal neutrality (LIS special regime) if conditions met; no immediate taxation | Seller taxed in year of closing (capital gain or corporate income) |
| Employees | Automatic subrogation; collective agreements unified (potential employment cost) | Share deal: automatic subrogation; asset deal if productive unit transfers |
| Contracts | Transfer automatically (universal succession) | Share deal: continue automatically; asset deal: require individual assignment |
| CNMC / regulatory | May require clearance if thresholds exceeded; greater scrutiny due to full integration | May require clearance if thresholds exceeded; partial acquisition may fall below thresholds |
| Timeline | 3–6 months minimum (formal LME process) | 2–4 months for share deal; 3–6 months for complex asset deal |
| Complexity | High: general meetings, expert reports, registry filings, operational unification | Medium-high: complex SPA; lower for simple share deals with sophisticated parties |
| Direct costs | Notary, Registro Mercantil, corporate operations tax (IOS, generally exempt), advisory fees | Notary, ITP on real estate in asset deals, M&A + legal advisory fees |
When to Use a Merger
The merger is the right structure in four main scenarios:
Full integration within the same group. When a parent company wants to absorb a wholly owned (100%) subsidiary, the simplified merger (Art. 49 LME) eliminates the requirement for an independent expert’s report and shareholder opposition rights. This is the most common corporate rationalisation operation in Spanish business groups: it reduces the cost of maintaining separate companies (annual accounts, general meetings, registry obligations) and simplifies the structure for management and shareholders alike.
Integration between family businesses or single-owner companies. When two companies share the same owner or controlling family, a merger allows complementary businesses to combine without triggering tax: shareholders receive participations in the resulting entity without recognising gains. This is the typical scenario of the Spanish family business that has accumulated multiple companies over time with different assets or activities, and now wants to rationalise the structure ahead of a generational transition or external sale.
Elimination of operational duplication. When two entities do essentially the same thing — overlapping teams, duplicated infrastructure, parallel systems — the merger forces complete integration. Unlike an acquisition where the subsidiary can operate semi-independently indefinitely, a merger requires genuine integration. This is both a risk (the integration process is more demanding) and an advantage (there is no temptation to defer integration until later).
Intra-group tax optimisation under fiscal neutrality. Where the merger qualifies for the special regime under Chapter VII, Title VII of the Corporate Income Tax Law (LIS), the gains realised in the operation are not taxed at the time of the merger — they are deferred until the assets are transferred to third parties. This fiscal neutrality regime is the primary reason mergers are chosen for patrimony reorganisations within family or corporate groups.
When to Use an Acquisition
The acquisition is the preferred structure when the buyer wants to maintain post-transaction flexibility.
Preserving brand and identity. If the acquired business has a valuable brand, a customer base loyal to that brand, or a sector reputation that would be lost in an integration, the acquisition allows the subsidiary to operate independently or semi-independently for years. A buyer that acquires a niche business with a strong brand and immediately merges it into its own structure typically destroys much of the value that justified the price paid.
Operational independence during transition. The acquisition gives the buyer time with integration. There is no statutory deadline requiring the integration of systems, teams or processes. A merger, once formalised, is irreversible: there is no going back if integration fails. The acquisition allows the buyer to test integration while the target remains a separate entity, and to execute a subsequent merger once the process is consolidated.
Protection against unknown liabilities. In a share deal, the buyer inherits the liabilities of the acquired company — but inherits them inside a separate legal entity with limited liability. If a serious unprovisioned contingency surfaces post-closing, the risk is compartmentalised in the subsidiary. In a merger, the risk of liabilities inherited from the absorbed company transfers directly to the absorbing company’s balance sheet.
Partial acquisition. An acquisition allows the buyer to purchase 51%, 60% or 80% of a business whilst retaining the minority shareholders in place. A merger, by contrast, requires integrating all shareholders (who receive participations in the absorbing or new entity in proportion to the exchange ratio). If the buyer wants to retain the founder with a residual stake as a retention incentive, the acquisition is the only viable option.
For the contractual and corporate aspects of either structure, our corporate transactions team manages the full process from merger plan to registry filing.
Three Spanish Case Studies
Case 1: CaixaBank and Bankia (2021) — Strategic Rescue Merger
The merger of CaixaBank and Bankia in 2021 is the largest banking merger in recent Spanish history: CaixaBank absorbed Bankia, creating the largest bank by assets in Spain with over €660 billion in combined assets. Bankia, which had been rescued with public funds in 2012, was extinguished as an independent entity.
The choice of merger by absorption was not purely financial: it was impossible to maintain Bankia as an independent entity with the State as majority shareholder (67% via the FROB) over the long term. The merger allowed the State to reduce its participation in the combined entity to 16%, with a gradual exit route. The formal merger process took approximately six months from announcement to registry registration.
The operational integration — IT systems, branch networks (approximately 1,500 branches closed in total), collective bargaining agreements — took a further two years. Integration costs were approximately €1.5 billion, but the expected synergies (€770 million annually from 2023 onwards) justified the process.
Case 2: Family Business Merger in the Same Sector — Regional Food Distribution
A very common pattern in Spain: two family businesses in the same regional sector (food distribution, construction, last-mile logistics), with owners who have known each other for decades, with children who do not want to take over the business, and individually too small to attract a private equity fund or sector consolidator. A merger allows them to create a larger entity that is attractive as an acquisition target within three to five years.
In these cases, the merger qualifies under the fiscal neutrality regime — the owners pay no capital gains tax on the exchange of participations — and the exchange ratio reflects the agreed relative valuations. The M&A advisers for both families also structure the shareholders’ agreement for the new entity, governing joint management, dividend policy and exit rights.
This pattern is directly relevant to international buyers seeking to consolidate fragmented Spanish sectors: understanding that the merger of two targets into one before the acquisition closes is a legitimate and tax-neutral pre-sale step changes how you approach the initial outreach and valuation.
Case 3: PE Acquisition of Spanish Subsidiary — Delivery Hero and Glovo
Delivery Hero acquired a majority stake in Glovo (a Spanish company) in 2022, completing the full acquisition in 2023. Rather than merging Glovo into the Delivery Hero structure, the German multinational maintained Glovo as a subsidiary operating under its own brand. The reason is precisely as described above: the Glovo brand has strong recognition in Spain, Italy and Latin America that justifies its maintenance as an independent entity.
The acquisition structure also allowed Delivery Hero to manage Glovo’s regulatory risks — in particular the classification of delivery riders under the Riders’ Law (Ley Rider) — in a compartmentalised way, without the subsidiary’s legal contingencies directly affecting the consolidated balance sheet.
This case illustrates a recurring logic in cross-border M&A into Spain: foreign buyers frequently use the acquisition structure precisely to contain Spanish employment and regulatory risk whilst retaining the commercial upside of a recognised local brand.
The Fiscal Dimension: The Neutrality Regime
The special regime under Chapter VII, Title VII of the LIS (Arts. 76 to 89) is the provision that allows mergers, spin-offs and non-cash contributions to be tax-neutral — that is, without generating immediate taxation.
To qualify for the regime, two principal conditions must be met:
Condition 1: Valid economic rationale. The operation must be carried out for “valid economic reasons” other than mere tax saving. The Spanish legislation is explicit: if the Spanish tax authority (AEAT) considers that the operation lacks economic substance and has as its primary objective a tax advantage, it can deny the neutrality regime and tax the gains as if the transaction had been taxed at ordinary rates. The most robust valid economic reasons are: restructuring of a business group, elimination of duplications, preparation for a future disposal, creation of scale.
Condition 2: Prior notification to the AEAT. The application of the regime must be notified to the tax authority before filing the corporate income tax return for the year in which the operation occurs. Failure to notify does not automatically preclude the regime, but can complicate its defence in a subsequent inspection.
The principal risks of the AEAT challenging the neutrality are: mergers between companies with significant carried-forward losses (BINPs) where the operation enables the use of those losses in a way that would not have been possible without the reorganisation; and mergers between entities of very different valuations where the exchange ratio implies a concealed wealth transfer between shareholders.
A prior binding ruling (consulta vinculante) from the Directorate General of Taxes (DGT) is a highly valuable tool in complex operations: the DGT’s confirmation of the regime’s applicability, if forthcoming, provides legal certainty against a subsequent inspection.
The intersection of merger structure and tax planning is complex enough that early coordination between your M&A and tax planning advisers is not optional — it is the difference between a tax-neutral reorganisation and an unexpected liability.
Decision Framework: Seven Questions
If you are planning a corporate reorganisation or transaction, these questions orientate you towards the correct structure:
- Do you want to fully integrate two businesses into a single entity? → Merger
- Do you want to maintain the operational independence of the acquired business post-closing? → Acquisition
- Are there minority shareholders who do not want to sell? → Acquisition (you cannot compel minorities in a merger without following a complex squeeze-out process)
- Do you want to defer the seller’s taxation? → Merger under the neutrality regime
- Do you want the buyer to be able to amortise goodwill for tax purposes? → Asset deal (acquisition of assets)
- Do you need to close quickly? → Share deal acquisition: it is the most agile process
- Does the target carry serious or poorly quantified liabilities? → Acquisition (risk remains compartmentalised in the subsidiary)
For a structured analysis of which option makes more sense in your specific situation, speak with our M&A team. You can also deepen your understanding from the buyer’s perspective in our guide on buying a business in Spain, and from the seller’s perspective in how to prepare your business for sale.
