EIN for Spanish LLC Owners: Why Where You Work From Matters More Than the LLC Itself

Three things before you apply. First, your LLC needs state approval -- applying before formation is complete is a common, avoidable delay. Second, keep your Spanish DNI or NIE accessible in case the IRS requests identity verification during a fax or phone follow-up. Third, settle on a mailing address for the CP 575 confirmation letter -- a Spanish home address works, though many founders use a US virtual mailbox for faster, trackable delivery. Worth deciding early: how you plan to document the LLC's genuine US-side substance (contracts, service delivery evidence, business rationale beyond tax savings) if any part of the operation is not run entirely from Spain, since that documentation becomes relevant to both the effective-management question above and the attribution question below.

The application process itself does not vary by country. Spanish founders use the same three non-resident routes as everyone else, since the IRS's online EIN system requires an SSN, ITIN, or US legal residence most applicants do not have. Fax is the most reliable method: complete Form SS-4 and send it to 855-215-1627 if faxing from within the US, or 304-707-9471 from outside -- i.e., from Spain -- with real-world turnaround commonly running one to two weeks despite the IRS's official four-business-day target. Phone, at 267-941-1099, is open to international applicants Monday through Friday, 6:00 AM to 11:00 PM US Eastern Time; Central European Time runs six hours ahead of Eastern, pushing the practical calling window into Spanish evening and night hours. Mail, at four to five weeks, is the slowest option and rarely worth choosing over fax.

A few fields on Form SS-4 consistently cause delays for non-resident applicants generally, Spanish founders included. Line 7b asks for the responsible party's SSN, ITIN, or EIN -- if you have none of these, the IRS's own instructions say to write Foreign or N/A, not leave the field blank, since a blank Line 7b is one of the most common reasons non-resident applications bounce back for correction. Lines 4a-4b need your full Spanish mailing address spelled out with Spain written in full, since that is where your EIN confirmation letter, Form CP 575, will be mailed if you apply by post. Line 9a asks about entity classification -- accepting the default disregarded-entity status is standard for most single-member LLCs and does not by itself resolve either the effective-management or attribution questions covered elsewhere on this page, since both are assessed under Spanish domestic law independently of the US election.

Spain layers its own reporting obligations on top of the IRS filings this series usually covers. Modelo 720 requires Spanish tax residents to declare foreign assets, including an interest in a foreign entity like a US LLC, once combined foreign holdings exceed 50,000 euros -- a threshold that a growing single-member LLC can cross well before it feels large by US standards. This form has a controversial history: the Court of Justice of the European Union ruled in 2022 that Spain's original penalty regime for late or inaccurate Modelo 720 filings was disproportionate, and Spain subsequently reformed the penalties, though the underlying reporting obligation itself remains in force. Separately, if your LLC falls under the attribution regime described above, Modelo 184 is the annual informative return used to report attributed income to Hacienda. Missing either filing is a compliance gap independent of whatever you owe the IRS, and one that tends to surprise founders who assumed their US paperwork was the whole picture.

Once issued, your EIN arrives with a confirmation letter, Form CP 575, sent by fax, mail, or both depending on your application method -- keep it permanently, since banks and payment processors will ask for it during account opening. A lost CP 575 cannot be reissued, but the IRS will provide an EIN Verification Letter, Form 147C, as a substitute for any future banking or tax need. From here, most Spanish founders move on to opening a US bank account -- Mercury and Relay both work for Spain-based founders, since Spain is not on either provider's restricted list -- and, since almost every non-resident-owned single-member LLC counts as a foreign-owned disregarded entity, filing Form 5472 alongside a pro forma Form 1120 annually, regardless of whether the LLC had US activity that year. The $25,000 minimum penalty for missing that filing is a separate obligation to the IRS, distinct from anything owed to Hacienda.

If a formation service is handling your EIN application, confirm that the responsible party listed on Line 7a is you, the actual owner -- not a staff member at the formation company. The IRS defines the responsible party as whoever ultimately owns or controls the entity's funds and decisions, identified by their real name and passport-based nationality. An EIN record that lists someone other than the actual owner creates a mismatch that can complicate matters later if a bank or payment processor needs to verify beneficial ownership, which is the same information reported separately under BOI/FinCEN rules. If a provider suggests listing anyone but you, treat it as a red flag rather than a convenience, regardless of how routine it sounds.

Assuming the effective-management test does not recharacterize your income as purely domestic, Spain generally analyzes a US single-member LLC under its regimen de atribucion de rentas -- an income-attribution regime under articles 86 to 90 of the LIRPF and article 6 of the LIS. Under this regime, the LLC itself is not a separate taxpayer; its profits are imputed directly to the Spanish resident owner in the year the LLC earns them, independent of whether any cash was actually distributed. This traces back to a 2006 Mutual Agreement (Acuerdo Amistoso) between Spain and the United States, which specifically addressed how LLCs and similar pass-through entities qualify for benefits under the bilateral tax treaty. There is a narrower, fact-specific counterpoint worth knowing: Directorate General for Taxes (DGT) rulings, including consulta V3074-22, have recognized that an LLC with genuine separate legal personality and real operational substance -- rather than functioning as a simple pass-through conduit -- may in some cases be taxed only on amounts actually distributed to the owner. Which side of that line your LLC falls on depends on facts a Spanish tax advisor needs to evaluate, not a box you check on Form SS-4. Spanish resident founders sometimes assume this attribution treatment is uniquely harsh compared to how other countries handle disregarded entities, but the underlying idea -- taxing pass-through income to the owner as it is earned -- is closer to how the US itself treats the LLC than it might first appear; what differs is that Spain applies its own progressive IRPF brackets to that income rather than US rates, and offers a foreign tax credit mechanism under the treaty to prevent the same income from being taxed twice in full.

For most countries in this series, the tax question starts with the LLC's classification. For a Spanish tax resident, it often starts one step earlier: where is the business actually run from? Spanish tax authorities (Hacienda) apply a substance-over-form test rooted in the concept of "effective management" -- if you make the strategic decisions, manage the clients, and run day-to-day operations from Spain, Hacienda can treat the income as Spanish-source self-employment activity, taxed as ordinary IRPF income, regardless of where the LLC is legally formed or what the LLC's own tax classification says. This matters because it is a different question from the one covered on most other pages in this series: it is not about how the LLC's profits get attributed to you, but about whether the income counts as the LLC's at all once it reaches Hacienda's desk. A US LLC with a Wyoming address and a Spain-based founder making every decision from a laptop in Madrid is exactly the profile this test was built to catch. None of this changes your IRS paperwork -- Form SS-4 has no field for where you physically work -- but it shapes how the income gets reported once you're back in Spain, and it is worth understanding before, not after, your first full tax year. This is not a theoretical risk confined to audits of large structures -- Spanish tax advisors report it as one of the more common findings in routine reviews of solo founders and freelancers who set up a US LLC primarily to access US payment processors or clients, while continuing to work exactly as they did before, from home, in Spain.

A few mistakes show up repeatedly. Assuming that forming the LLC in a US state automatically makes its income foreign-source for Spanish purposes, when running the business entirely from Spain can trigger the effective-management recharacterization covered above regardless of the LLC's home state. Treating the attribution regime as optional or something that only applies if you choose to distribute profits, when article 86-90 LIRPF imputes income annually whether or not cash was withdrawn. Missing Modelo 720 once the 50,000 euro foreign-asset threshold is crossed, often because founders track US bank balances but not the LLC's total asset value as a foreign holding. And, as with every non-resident applicant regardless of country, leaving Line 7b of Form SS-4 blank instead of writing Foreign, which remains one of the most frequent reasons the IRS returns a non-resident application for correction.