The 10% Question: US Forms for European Co-Ownership

The first paperwork for a European second home should not feel like a tax seminar. It should answer three ordinary questions: what am I buying, who owns the property, and what information will I receive each year? For an American buyer, those answers also determine whether the purchase belongs on one or more US international information returns.

The distinction is easy to miss because the consumer language is simple. A home may be advertised as a 1/8 co-ownership share, typically associated with around six weeks of annual use. Yet “1/8” can describe different legal arrangements. The buyer might acquire a directly registered interest in real estate, stock in a foreign corporation, an interest in a foreign partnership, or an interest in another entity that owns the home. Exact nights, peak-season rights, costs and resale rules then come from the specific contract.

The encouraging point is that this is planning work, not a reason to avoid the purchase. A clean ownership chart and a short conversation with a US adviser before closing can identify the likely forms while the operator still has every document to hand. The expensive version is discovering the structure after the tax return is due.

One marketed share, several possible legal structures

Co-ownership is not the same as a contractual timeshare. The buyer acquires an ownership interest in property or in an entity that owns it, depending on the arrangement. That final phrase matters particularly to US taxpayers.

Consider a current Brixen, Tyrol listing offered through COP. Checked on 26 September 2026, it is advertised at €145,000 for a 1/8 share, with a minimum of 44 nights a year. The public listing describes real, deeded property ownership. Those details make it a useful home to investigate, but they do not replace the transaction documents. An American buyer would still ask precisely what appears on the Austrian register, whether an entity sits between the buyer and the property, and how joint ownership is recorded.

A different European home might place the real estate in a local company and transfer shares in that company. The economic experience can look similar—managed stays, shared costs, a resale process—but the US reporting analysis can be quite different. Never infer “12.5% of a foreign company” merely from the words “1/8 share”. Equally, do not assume that calling an arrangement deeded removes every US filing question. Read the ownership documents first.

The arithmetic is simple; the tax result is not

One eighth is 12.5%. That sits above a 10% threshold used in several IRS regimes. The important question is whether the buyer actually owns 12.5% of the voting power, value, capital or profits of a foreign entity under the relevant rules.

If the interest is stock in a foreign corporation, the current IRS instructions for Form 5471 describe a Category 3 filer as, among others, a US person who acquires stock and meets a 10% test. The threshold is 10% or more of the corporation's total stock value or total combined voting power. An actual 12.5% corporate interest can therefore make Form 5471 a pre-closing question.

If the entity is treated as a foreign partnership for US tax purposes, Form 8865 uses a related but not identical framework. Its Category 4 rules include an acquisition that takes a buyer from below 10% to a direct interest of 10% or more. A contribution of cash or other property in exchange for the interest can also bring the Category 3 rules into view.

These are not interchangeable labels. A locally incorporated company may be classified differently for US tax purposes, and an entity may have made a classification election. Attribution rules can also change the result for spouses, family members and interests held through another vehicle. If two spouses are described commercially as splitting one 1/8 share, it is unsafe to conclude that each simply owns 6.25% for every US test.

Four forms to put on the first adviser agenda

The transaction path matters as much as the percentage. The IRS's Form 926 guidance addresses transfers of property to a foreign corporation. A subscription for newly issued shares is not automatically the same transaction as purchasing an existing share from another owner. Buyers should give the adviser the payment flow, not simply the brochure.

Some forms relate primarily to the acquisition year; others can recur annually if their conditions continue to be met. The operator should therefore explain what accounts, valuations and ownership information will be available after completion. A promise that “your accountant will handle it” is not enough if the accountant cannot obtain the entity records.

Form 8938 follows the wrapper

The IRS draws a clear distinction between directly held foreign real estate and an interest in a foreign entity. Its Form 8938 guidance says that foreign real estate held directly is not itself a specified foreign financial asset. If the property is held through a foreign corporation, partnership, trust or estate, however, the interest in that entity can be reportable when the buyer's combined specified foreign financial assets exceed the applicable threshold.

For taxpayers living in the United States, the IRS currently states thresholds of more than $50,000 at year-end or $75,000 at any point for an unmarried person or someone filing separately. For a married couple filing jointly, the figures are more than $100,000 at year-end or $150,000 at any time. Higher thresholds apply to qualifying taxpayers living abroad: more than $200,000/$300,000 for a non-joint filer and $400,000/$600,000 for joint filers.

Those limits apply to the aggregate foreign financial assets, not just the holiday-home interest. A buyer with existing foreign accounts or investments can cross the line even if the new share appears modest in isolation. Conversely, the presence of a foreign home does not by itself prove that Form 8938 is due.

Where an interest is already reported on Form 5471, 8865 or certain other international forms, the Form 8938 rules may allow the filer to identify the other form rather than repeat all the asset detail. That is administrative coordination, not an exemption from asking the question.

FBAR is a different test

Form 8938 and the FBAR are often mentioned together, but they do not report the same things. The IRS comparison table states that foreign stock and foreign partnership interests held outside a financial account can belong on Form 8938, while those interests are not themselves reported on the FBAR.

The FBAR focuses on foreign financial accounts. A separate issue can arise if the buyer has a financial interest in, or signature or other authority over, a foreign bank or securities account and the aggregate account value exceeds $10,000 at any time in the year. A minority co-owner should not assume that the home's operating account is automatically their personal FBAR account; nor should someone with signing authority assume it is irrelevant. Ask who controls the bank account and what authority the buyer receives.

Do not leave the PFIC question until resale

If the ownership vehicle is a foreign corporation, ask whether the passive foreign investment company rules have been reviewed. Form 8621 is used by certain direct or indirect shareholders of a PFIC. The tests look at the corporation's income and assets, and the analysis can be technical for a company that primarily holds a home, maintains cash reserves or permits rental.

This is not a statement that every property company is a PFIC. It is a reason to obtain a written answer early, while elections and record-keeping choices can still be considered. Personal use, limited rental and management activity do not translate neatly into a universal result.

The local tax file still matters

US information reporting does not replace the rules where the property sits. Purchase taxes, registration costs, annual property or entity charges, local reporting and tax on rental or resale depend on the country, region and legal structure. Foreign tax credits may help prevent double taxation in some circumstances, but their availability, category and timing need individual advice.

The practical response is to appoint advisers who can exchange information. The local lawyer should provide the executed ownership and management documents, while the US adviser identifies the classification and filing consequences. If translations are needed, commission them before the first US return rather than during filing season.

This also fits the wider compliance journey. European lawyers and agents will usually request evidence of identity and source of funds before completion. COP's guide to proving where purchase funds came from explains why a tidy document file speeds up that process.

The pre-closing document pack

Before sending a deposit or subscription payment, ask for a pack that a US international tax adviser can review in one sitting:

• Ownership chart: the property, every entity in the chain and the buyer's exact percentage of vote, value, capital and profits.
• Transaction path: whether the buyer acquires an existing interest, subscribes for a new one, advances a shareholder loan or combines several steps.
• Governing documents: deed, articles, shareholder or partnership agreement, management agreement and booking rules.
• Classification history: the entity's legal form, fiscal year and any US tax classification election known to the operator.
• Annual information: accounts, tax returns, ownership statements, distributions, debt and any rental income or expenses.
• Identifiers and contacts: foreign tax number, registered address and the person responsible for supplying annual records.
• Exit mechanics: resale process, transfer restrictions, fees, rights of first refusal and how sale proceeds are documented.

The buyer should also ask who pays for specialist reporting and whether the management budget includes any entity-level accounting needed by international owners. A share that is easy to enjoy should also be easy to document.

A calm way to make the decision

The purpose of this exercise is confidence. A good co-ownership structure should withstand simple questions and produce clear paperwork. It should tell the buyer what they own, how the calendar works, how costs are shared and how the interest can later be sold. The US overlay then becomes a defined annual task rather than an unpleasant surprise.

COP acts as an introducing platform, not as the operator, lawyer or tax adviser. We can identify current homes and request the property documents; buyers should take independent US and local advice before relying on a particular classification or filing position. Our How It Works guide explains the broader purchase journey.

Frequently asked questions

Does every 1/8 share trigger Form 5471?

No. Form 5471 concerns interests in foreign corporations. A marketed 1/8 share might instead be directly held real estate or an interest in a partnership, and the buyer's percentage under US attribution rules may differ from the headline fraction. The transaction documents decide which question to ask.

If I own foreign real estate directly, must it go on Form 8938?

The IRS says directly held foreign real estate is not itself a specified foreign financial asset. An interest in a foreign entity that owns real estate can be reportable if the buyer exceeds the applicable aggregate threshold.

Is a 1/8 entity interest above the IRS 10% threshold?

Mathematically, yes: 1/8 is 12.5%. Legally, confirm that the buyer truly receives 12.5% of the relevant vote, value, capital or profits and consider attribution or joint-ownership rules.

Does the co-ownership share itself go on an FBAR?

Foreign stock or a foreign partnership interest held outside an account is not itself an FBAR financial account. A separate FBAR obligation can arise if the buyer has a qualifying financial interest in or authority over foreign accounts and the aggregate account threshold is exceeded.

Will these forms mean extra tax is due?

Not necessarily. Forms 5471, 8865, 8938, 926 and 8621 are information or specialised tax forms with different purposes. Reporting a purchase is not the same as owing tax, although income, distributions, rental or resale may create tax consequences.

When should an American buyer speak to an adviser?

Before signing or transferring funds. The adviser needs the proposed ownership chart and payment flow. Advice is more useful when the structure can still be clarified and the operator can commit to supplying annual records.

Sources and data notes

US reporting thresholds and descriptions were checked on 26 September 2026 against the current IRS pages and instructions for Form 5471, Form 8865, Form 8938 and FATCA reporting, Form 926, the Form 8938/FBAR comparison and Form 8621. The Brixen asking price, share size and minimum annual nights were checked against the live COP listing on the same date. This article is general information, not US, Austrian or other legal or tax advice.

Ready to look at the home as well as the paperwork? Browse current Austrian co-ownership properties or ask COP for the ownership documents behind a particular listing.