S-Corp and C-Corp for Spanish Residents: Full Tax Analysis

Why S-Corp and C-Corp Owners Face Different Problems in Spain

When US shareholders of S-Corporations or C-Corporations become tax resident in Spain, they enter a world where the same legal entity is classified and taxed in fundamentally different ways on each side of the Atlantic. The S-Corporation hybrid mismatch is one of the most technically complex — and financially damaging — situations in US-Spain tax planning. The C-Corporation presents a different but equally significant set of challenges.

This guide provides a detailed analysis of both entity types from the perspective of a Spanish tax resident, covering the hybrid mismatch problem, GILTI, Subpart F income, and planning options. It builds on the general LLC analysis and focuses specifically on the corporate election structures that create the greatest compliance complexity.

The S-Corporation: A Hybrid That Spain Does Not Recognise

An S-Corporation is a US tax election available to eligible domestic corporations (American corporations with eligible shareholders, single class of stock, maximum 100 shareholders — all US persons). Under IRC §1361-1368, an S-Corp is a pass-through entity: income, losses, deductions and credits flow directly to shareholders in proportion to their ownership, regardless of whether distributions are made.

From a US federal perspective, the S-Corp shareholder pays income tax on the corporation's profits in the year those profits are earned — whether or not any cash is distributed. This means a shareholder who owns 100% of an S-Corp generating $300,000 of profit pays US income tax on $300,000, even if $200,000 is retained in the company.

Spain's position is the opposite. Spain does not recognise the S-Corp election. The AEAT applies the same analysis it uses for all foreign entities: the S-Corporation has limited liability shareholders (it is, after all, a corporation), therefore it is classified as opaque — equivalent to a Spanish SA or SL. Spain will only tax the shareholder when dividends are actually distributed.

The Hybrid Mismatch in Practice

This creates the classic hybrid mismatch that can result in economic double taxation:

• Year 1: S-Corp earns $300,000. US taxes the shareholder on $300,000 (pass-through). Spain does not tax anything — no distribution has been made.
• Year 2: S-Corp distributes $200,000 to the shareholder. US does not tax this (it was already taxed in Year 1 — this is a non-taxable return of previously taxed basis). Spain taxes the $200,000 as a dividend at savings income rates (19-28%).
• Result: The same $200,000 has been taxed twice — once in the US as earned income (pass-through), once in Spain as a dividend. There is no foreign tax credit available in Spain because Spain is taxing a dividend (distributed in Year 2) while the US tax was paid on income attributed in Year 1 — the timing and character do not match.

GILTI: The Global Intangible Low-Taxed Income Problem

GILTI (Global Intangible Low-Taxed Income) under IRC §951A is a US anti-deferral regime that applies to US shareholders of Controlled Foreign Corporations (CFCs) — generally US persons owning 10%+ of a foreign corporation. GILTI requires shareholders to include in their US taxable income each year a portion of the CFC's net income that exceeds a 10% return on its depreciable assets.

For Spanish residents who are also US citizens or US persons, GILTI creates a particular complication. If a US citizen resident in Spain owns a Spanish SL (or other foreign corporation from a US perspective), the Spanish company's profits may be subject to GILTI inclusion in the US. This means the shareholder pays US tax on the Spanish company's profits as they arise — regardless of any Spanish corporate tax paid at the SL level, and regardless of whether dividends are distributed.

The interaction with Spanish tax is complex:

• GILTI inclusions are treated as ordinary income for US purposes, eligible for a 50% deduction under §250 (resulting in an effective rate of 10.5% for corporate taxpayers, though individual shareholders cannot access this deduction).
• Spain will separately tax dividends from the SL when distributed, at savings income rates (19-28%).
• The foreign tax credit for Spanish corporate tax paid at the SL level is limited by GILTI's basket rules — the credit may not fully offset the US GILTI tax.

For individual US citizens in Spain (not holding through a US corporation), GILTI can result in a US tax charge on Spanish corporate profits before Spain taxes the same profits again upon distribution — a genuine double taxation scenario that requires expert modelling.

Subpart F Income: Another Attribution Regime

Subpart F income (IRC §952) is another US anti-deferral regime applicable to CFCs. Unlike GILTI, which applies broadly to all CFC income exceeding a minimum return on assets, Subpart F targets specific categories of passive and base-eroding income — including dividends, interest, royalties, rents, and certain sales and services income from related parties.

For Spanish residents with foreign holding companies or passive investment structures, Subpart F can require them to include the CFC's passive income in their US taxable income on a current basis. This creates the same timing mismatch problem as the S-Corp hybrid: the US taxes attributed income as it arises; Spain taxes the same income as dividends only when distributed. Without careful credit planning, the result is double taxation.

The C-Corporation: Simpler but Doubly Taxed

The C-Corporation is opaque on both sides of the Atlantic — both the US and Spain treat it as a separate taxable entity. This eliminates the hybrid mismatch but creates classic economic double taxation:

• Level 1: The C-Corp pays US federal corporate tax at 21% on its profits.
• Level 2: When dividends are distributed to a Spanish-resident shareholder, Spain taxes those dividends at savings income rates (19-28%).
• US withholding: The US may also withhold tax on dividends paid to non-resident shareholders, though the Spain-US treaty limits this to 15% (or 5% for qualifying corporate shareholders). The Spanish shareholder can credit this withholding against their Spanish tax on the dividend income under Art. 80 LIRPF.

The effective combined tax burden on C-Corp profits ultimately distributed to a Spanish resident is significant: 21% at the US corporate level, 15% US withholding (after treaty reduction), and then Spanish IRPF at savings rates net of the withholding credit. Careful modelling is required to quantify the actual net position.

The Beckham Law: A Potential Solution for Foreign Corporate Income

One of the most powerful planning tools for US executives moving to Spain is the Beckham Law (Art. 93 LIRPF). Under this special regime, qualifying Spanish residents pay a flat 24% on Spanish-source employment income for up to six years — and critically, foreign-source income is generally exempt from Spanish taxation.

For S-Corp or C-Corp shareholders who qualify for the Beckham Law:

• Dividends from a US S-Corp or C-Corp received during the Beckham period may be classified as foreign-source income and exempt from Spanish IRPF.
• This eliminates the Spanish layer of taxation during the Beckham period, leaving only the US tax obligations to manage.
• The Beckham exemption for foreign income interacts with the US foreign earned income exclusion (FEIE) and foreign tax credit regime — careful coordination is required to avoid inadvertently reducing US credits on income that is also exempt in Spain.

The Beckham Law can therefore be an excellent transitional tool: apply it for six years while systematically restructuring the US corporate holdings into a Spain-compatible structure that avoids the hybrid mismatch problem in the long term.

When to Convert: S-Corp vs C-Corp vs Spanish SL

The optimal structure for a Spanish resident depends on their income level, the nature of the business, the duration of planned Spain residency, and whether they are US citizens or non-citizens. Key decision points:

• Short-term Spain residency (under 6 years): Beckham Law combined with maintaining the US structure may be optimal. Eliminate the Spanish layer during the Beckham period and restructure before re-entering general IRPF.
• Long-term Spain residency, US citizen: Consider converting the S-Corp to a C-Corp (eliminating the hybrid mismatch) and optimising the withholding structure under the Spain-US treaty. Alternatively, establish a Spanish SL for Spanish operations and maintain the US structure for US-source business.
• Long-term Spain residency, non-US citizen: Closing the US corporate structure and operating through a Spanish SL (with proper Spanish IS and IRPF planning) is often the most tax-efficient long-term solution.

Spanish Reporting Obligations for US Corporation Owners

Beyond the income tax issues, Spanish residents who own US corporations face significant annual reporting obligations:

• Modelo 720: Foreign asset declaration. Shares in a US corporation with a value exceeding €50,000 must be declared annually (on first declaration and whenever any category increases by more than €20,000). Penalties for non-compliance, while reduced after the ECJ ruling in C-788/19, remain significant.
• Modelo 100 (IRPF): Dividends received must be declared on the annual IRPF return, with the applicable foreign tax credit claimed.
• Modelo D-6: Annual declaration of foreign investments (shares in foreign companies) to the Ministerio de Economía — separate from the AEAT's Modelo 720.
• FBAR (FinCEN 114) and Form 8938: US reporting obligations for US citizens with Spanish bank accounts and financial assets.