What your LLC is —and isn't— for the tax authority. Show this to your accountant.
Many advisors in Spain haven't seen a single-member US LLC before and, out of caution, treat it as the worst case: an opaque foreign company. It isn't. This is the plain explanation, no jargon, so your accountant understands how it actually taxes —and stops treating you like an odd case.
A single-member LLC (one owner) is a fiscally transparent entity: to the US it's a disregarded entity —it "doesn't exist" for tax purposes— and its income is attributed directly to the owner. For Spain, that means look-through: the person (your client) is taxed in their IRPF on worldwide income, not a separate opaque company. The LLC doesn't hide the income: it passes it through to you.
· A real US company with its Operating Agreement, EIN and registered agent.
· Transparent: its income is taxed in the owner's IRPF.
· A common legal structure for billing international clients.
· An opaque company to hide income from the tax authority.
· A "tax haven" that avoids taxing in Spain.
· Something that replaces the owner's Spanish obligations (IRPF, and Modelo 720 where applicable).
Even though it's transparent, the LLC has informational obligations in the US: Form 1120 pro-forma + Form 5472 every year (informational; it pays no federal tax with no income effectively connected to the US), the FBAR if it has accounts outside the US over $10,000, and the BEA's BE-13 survey at formation. The federal set that applies is FBAR + BEA. What it does NOT file is the BOIR: since March 2025 FinCEN exempts US companies. (The Spanish obligations —IRPF, 720— are yours to handle as the advisor; here we only clarify the US side.)
Operating Agreement + EIN/CP-575
They prove the LLC exists, who controls it and its federal tax number.
Proof of substance and bookkeeping
Income, expenses, contributions and draws — the company's operational reality.
The year's US tax filing (1120 + 5472)
The federal informational filing. Plus the FBAR/BE-13 when they apply.
The Defense Folder
If the client has it, all of the above comes gathered, dated and sealed (SHA-256 + timestamp).
Your client can bring you all of this, gathered and up to date
Devil Club maintains the US structure's documentation so you work with real paper, not screenshots. Your client answers for their IRPF and their 720; we answer for the US side being complete and verifiable.
See the Defense Folder The Manager planThis page is general information to make the advisor's work easier, not legal or tax advice, and does not replace the judgment of the client's advisor in Spain. Devil Club is not a law firm or a tax practice: we document and maintain the LLC's US structure; taxation in Spain is determined and filed by the taxpayer's gestor or tax advisor.