LLC documents: which ones you need and how to keep them organized

6 must-have documents. When you form a US LLC, you receive several official documents. We explain what each means and how to organize them.

A properly formed LLC's legal kit contains 6 must-have documents: Articles of Organization, Operating Agreement, EIN Confirmation Letter (CP 575), BOI Report (if applicable), Registered Agent Acceptance, and Banking Resolution.

When you form a US LLC, you receive a complete "legal kit". several documents, each with a specific function. At Exentax we prepare and deliver all of them as part of the formation service. But it's good to know what each one is and when you'll need it.

Key points

1. Articles of Organization (Certificate of Formation)

This is the official document that registers your LLC with the state. It's the "birth certificate" of your company. It's public and contains:

Legal name of the LLC
Registered Agent address
Date of formation
Management type (Member-Managed or Manager-Managed)
State of formation

In states like New Mexico, member data does NOT appear in the Articles of Organization, giving you additional privacy.

When you need it: To open your bank account on Mercury or Relay, register on Stripe/PayPal, and prove your LLC exists legally. It's the first document anyone asks for.

2. EIN Letter (CP 575 / SS-4 Confirmation)

The EIN (Employer Identification Number) is your LLC's tax identification number with the IRS. It's equivalent to the NIF/CIF in Spain, RFC in Mexico, NIT in Colombia, or CUIT in Argentina. The CP 575 letter from the IRS officially confirms your EIN assignment.

When you need it: To open bank accounts (Mercury, Relay), register on Stripe/PayPal, file tax returns (Form 5472 + 1120), work with US clients (W-8BEN-E), configure Slash and Wallester, and file the BOI Report. Some banks specifically request the CP 575 letter for verification.

3. Operating Agreement

The most important internal document of your LLC. Defines the rules: who manages it, how profits are distributed, tax classification (Disregarded Entity), authorization to operate bank accounts, etc.

A key detail: the Operating Agreement is a private document. It's not registered with any state authority. Only you and the entities you choose (Mercury, Stripe) see it. This is a huge privacy advantage compared to structures like the Spanish SL.

When you need it: To open accounts on Mercury (they always ask for it), verify Stripe, and as legal backup for your entire structure.

4. Certificate of Good Standing

Issued by the state, it certifies that your LLC is current with all its obligations (Annual Report, fees, etc.). Think of it as your company's "clean record."

When you need it: Some banks and providers request it periodically. Also necessary if you register your LLC in another state (Foreign Qualification) or if a large client requests verification. Mercury may request it during periodic compliance reviews.

5. BOI Report Confirmation

The BOI Report (Beneficial Ownership Information) is a declaration to FinCEN identifying the real owners of the LLC. Since 1 January 2024, all LLCs must file it. Penalties for non-compliance: $591/day civil, up to $10,000 + 2 years criminal. And if a notice does land, at Exentax we keep the dossier ready so you reply in hours, not weeks.

When you need it: Within 90 days of formation (for new LLCs). Then, whenever there are changes in ownership or reported information (within 30 days of the change).

6. Registered Agent Agreement

Document confirming who your Registered Agent is. the person or company designated to receive official legal documentation on behalf of your LLC in the state of formation.

When you need it: Part of your LLC records. Some banks request it as additional verification.

Summary: your document checklist

Documents you do NOT need

Social Security Number (SSN): Not required for non-residents. The EIN replaces the SSN for LLC tax purposes
Visa or work permit: You don't need authorization to work in the US to have an LLC. Everything is 100% online
Physical US address: The Registered Agent provides the legal address
US passport: Any valid passport works
Pre-existing US bank account: Opened as part of the formation process
ITIN: Not needed for LLC formation or Mercury (but PayPal Business may require the owner's ITIN)

Where to keep these documents

We recommend having an organized digital copy of everything:

"LLC Docs" folder in your cloud (Google Drive, Dropbox, etc.)
Subfolders by type: Formation, Tax, Banking, Compliance
Clear names: "Articles_of_Organization_MyLLC.pdf", "EIN_Letter_CP575.pdf", "Operating_Agreement_MyLLC.pdf"

You'll need these documents every time you open a new account, register with a payment processor, or a large client requests verification. Having them organized saves you hours.

At Exentax, all our clients receive their complete documentation, organized and ready from day one.

Document lifecycle: when to update each document

Frequently asked questions about documents

Can I use digital copies of my documents?

Yes, for most purposes. Mercury, Stripe, and other platforms accept scanned copies. However, keep the original signed Operating Agreement in a safe place.

What if I lose a document?

Articles of Organization: Request a certified copy from the state ($10-25 fee)
EIN Letter: Request a replacement from the IRS (free but slow)
Operating Agreement: If you lose the original, you need to re-execute a new one
BOI Report: Request confirmation from FinCEN's portal

Do documents need to be notarized?

Generally no. US LLC documents don't require notarization. The Operating Agreement just needs signatures from all members.

Are my documents public?

Only the Articles of Organization are publicly searchable (varies by state). In New Mexico, member names don't appear in public records. The Operating Agreement, EIN letter, and other documents are private.

A couple of adjacent reads worth having open alongside this one: Why open a US LLC today: the 5 pillars of the American advantage and EIN vs ITIN vs SSN: the US tax identification numbers explained, which sharpen exactly the edges we skimmed above.

Legal and regulatory references

This article relies on rules currently in force. Main sources for verification:

United States. Treas. Reg. §301.7701-3 (entity classification / check-the-box); IRC §882 (tax on foreign income effectively connected with a US trade or business); IRC §871 (FDAP and withholding on non-residents); IRC §6038A and Treas. Reg. §1.6038A-2 (Form 5472 for 25% foreign-owned and foreign-owned disregarded entities); IRC §7701(b) (tax residency, substantial presence test); 31 U.S.C. §5336 (Corporate Transparency Act, BOI Report to FinCEN).
Spain. Law 35/2006 (LIRPF), arts. 8, 9 (residency), 87 (income attribution), 91 (CFC for individuals); Law 27/2014 (LIS), art. 100 (CFC for companies); Law 58/2003 (LGT), arts. 15 (anti-abuse) and 16 (simulation); Law 5/2022 (Form 720 penalty regime after CJEU C-788/19 of 27/01/2022); RD 1065/2007 (Forms 232 and 720); Order HFP/887/2023 (Form 721 crypto). Now is the moment to ask for help. At Exentax we open the case, file what is missing and reply to the relevant authority for you.
Spain–US treaty. BOE of 22/12/1990 (original DTT); Protocol in force since 27/11/2019 (passive income, limitation on benefits).
EU / OECD. Directive (EU) 2011/16, amended by DAC6 (cross-border arrangements), DAC7 (Directive (EU) 2021/514, digital platforms) and DAC8 (crypto-assets); Directive (EU) 2016/1164 (ATAD: CFC, exit tax, hybrid mismatches); OECD Common Reporting Standard (CRS).
International framework. OECD Model Convention, art. 5 (permanent establishment) and Commentaries; BEPS Action 5 (economic substance); FATF Recommendation 24 (beneficial ownership).

Applying any of these rules to your specific case depends on your tax residency, the LLC's activity and the documentation you keep. This content is informational and does not replace personalized professional advice.

A balanced banking stack: Mercury, Relay, Slash and Wise

There is no perfect account for an LLC. There is the right stack, where each tool plays a role:

Mercury (operated as a fintech with partner banks (Choice Financial Group and Evolve Bank & Trust primarily; Column N.A. on legacy accounts), FDIC via sweep network up to the current limit). Main operating account for non-residents with strong UX, ACH and wires. Still one of the most proven options to open from outside the US.
Relay (backed by Thread Bank, FDIC). Excellent backup account and for envelope-style budgeting: up to 20 sub-accounts and 50 debit cards, deep QuickBooks and Xero integration. If Mercury blocks or asks for KYC review, Relay keeps your operations running.
Slash (backed by Column N.A. (federally chartered, FDIC)). Banking built for online operators: instant virtual cards by vendor, granular spend controls, cashback on digital advertising. The natural complement when you manage Meta Ads, Google Ads or SaaS subscriptions.
Wise Business (multi-currency EMI, not a bank). To collect and pay in EUR, GBP, USD and other currencies with local bank details and mid-market FX. Does not replace a real US account but is unbeatable for international treasury.
Wallester / Revolut Business. Wallester provides corporate cards on a dedicated BIN for high volume. Revolut Business works as a European complement, not as the LLC's main account.

The realistic recommendation: Mercury + Relay as backup + Slash for ad operations + Wise for FX treasury. This setup minimizes block risk and reduces real cost. At Exentax we open and configure this stack as part of incorporation.

Next steps

Now that you have the full context, the natural next step is to map it against your own situation: what fits, what doesn't, and where the nuances depend on your residency, your activity and your volume. A quick review of your specific case usually saves a lot of noise before taking any structural decision.

Banking and tax facts worth clarifying

Fintech and CRS information evolves; here is the current state:

Before going further, put numbers on your case: the Exentax calculator compares, in under 2 minutes, your current tax bill with what you would carry running a US LLC properly declared in your country of residence.

> Start today, 100% online

Notes by provider

Mercury operates with several federally chartered partner banks and FDIC coverage via sweep network: mainly Choice Financial Group and Evolve Bank & Trust, with Column N.A. still in some legacy accounts. Mercury is not itself a bank; it is a fintech platform backed by those partner banks. If Mercury closes an account, the balance is typically returned by paper check mailed to the account holder's registered address, which can be a serious operational problem for non-residents; keep a secondary account (Relay, Wise Business, etc.) as contingency.
Wise ships two clearly different products: Wise Personal and Wise Business. For an LLC you must open Wise Business, not the personal account. Important CRS nuance: a Wise Business held by a US LLC sits outside CRS because the account holder is a US entity and the US is not a CRS participant; the USD side operates via Wise US Inc. (FATCA perimeter, not CRS). In contrast, a Wise Personal opened by an individual tax-resident in Spain or another CRS jurisdiction does trigger CRS reporting via Wise Europe SA (Belgium) on that individual. Opening Wise for your LLC does not bring you into CRS through the LLC; a separate Wise Personal in your own name as a CRS-resident individual does report.
Wallester (Estonia) is a European financial entity with an EMI/issuing-bank licence. Its European IBAN accounts are within the Common Reporting Standard (CRS) and therefore trigger automatic reporting to the tax administration of the holder's country of residence.
Payoneer operates through European entities (Payoneer Europe Ltd, Ireland) that are also in scope for CRS for clients resident in participating jurisdictions.
Revolut Business: when paired with a US LLC, it operates under Revolut Technologies Inc. with Lead Bank as its US banking partner. The account delivered is a US account (routing + account number); no European IBAN is issued to a US LLC. The European IBANs (Lithuanian, Belgian) belong to Revolut Bank UAB and are issued to European clients of the group. If you are offered a European IBAN tied to your LLC, confirm exactly which legal entity holds that account and which regime it reports under.
Zero tax: no LLC structure delivers "zero tax" if you live in a country with CFC/tax transparency or income attribution rules. What you achieve is no double taxation and correct reporting at residence, not elimination.

The living file of your LLC: what you keep and why it matters

The LLC is not sustained by the first-day formation: it is sustained by a file that grows and is updated. When the bank shows up with enhanced KYC, a gateway with verification, an inspection or a potential buyer, specific paperwork is requested - and the difference between having it in an hour or in three weeks decides account closures and payment blocks. Relax: at Exentax this is what we do every week, we close it before the letter ever lands in your inbox.

Constitutive block. Articles of Organization stamped by the Secretary of State, Operating Agreement signed by all members, EIN Confirmation Letter (CP-575 or 147C), recent Certificate of Good Standing and updated Registered Agent designation. Without these five documents you do not open a serious account or sign a sizable contract.
Identity and compliance block. Owner ITIN or SSN if applicable, FinCEN BOI Report acknowledgment (with TC and proof), valid passport, recent proof of address and the latest state Annual Report with franchise tax paid. One outdated item and the bank freezes onboarding.
Fiscal and banking block. Forms 5472 + 1120 pro forma for the last three years, owner's tax-residency statement, Mercury/Relay/Wise statements for the last six months and reconciliation with bookkeeping. This is what Stripe Risk asks for in an extended KYC review.
Contractual block. Live Operating Agreement (with resolutions for material changes), agreements with critical providers (registered agent, mailing, banking, payment processors) and, if there are partners, the intra-group agreements. Transfer-of-interest and right-of-first-refusal clauses live here.

What we are asked the most

What is the difference between CP-575 and 147C? The CP-575 is the original letter the IRS issues when assigning the EIN; it is printed only once. If you lost it, you request a 147C calling the IRS - it takes 5-10 days and serves the same purpose for banking.

How long to keep everything? Minimum 7 years for IRS purposes on the tax forms; we recommend indefinite for formation, BOI and Operating Agreement. A future sale of the LLC will thank you.

At Exentax we keep that file alive inside the annual retainer and deliver it in banking-ready or due-diligence-ready format whenever you need it.

Legal & procedural facts

FinCEN and IRS reporting requirements moved recently; the current state is:

BOI / Corporate Transparency Act: your LLC is NOT required to file (a competitive advantage). After FinCEN's March 2025 interim final rule, the BOI Report obligation was narrowed to "foreign reporting companies" (entities formed OUTSIDE the US and registered to do business in a state). A US-formed LLC owned by a non-resident does NOT file the BOI Report: one fewer filing on your calendar, less paperwork, and a cleaner structure than ever. If your LLC was formed before March 2025 and you already filed BOI, keep the acknowledgement. The regulatory status can change again: we monitor FinCEN.gov on every filing and, if the obligation comes back, we handle it at no extra cost. Current status verifiable at fincen.gov/boi.
Form 5472 + pro-forma 1120. For a Single-Member LLC owned by a non-resident, the final regulations of Treas. Reg. §1.6038A-1 (in force since 2017) treat the LLC as a corporation for 5472 purposes. Procedure: pro-forma Form 1120 (header only: name, address, EIN, tax year) with Form 5472 attached. It is filed by certified mail or fax to the IRS Service Center in Ogden, Utah, not e-filed via standard MeF. Due date: April 15; extension via Form 7004 to October 15. Penalty: $25,000 per form per year, plus $25,000 per additional 30 days of non-filing after IRS notice.
Substantive Form 1120. Only applies if the LLC has filed a check-the-box election to C-Corp (Form 8832): it then pays 21 % federal corporate tax and files a substantive 1120. A standard disregarded LLC does not file a substantive 1120 and does not pay federal corporate tax.
EIN and notice. Without an EIN you cannot file 5472 or BOI. The IRS does not warn before imposing penalties; you find out when an EIN is flagged or a later filing is rejected.

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For state-specific details, see our Wyoming LLC service page with closed costs and timelines.

If your priority is the ITIN, see Get your ITIN with Exentax and we'll handle it in parallel.

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