For UK and European entrepreneurs who form a US LLC, the formation process often feels like the finish line. In many states, creating an LLC simply involves filing a short document and paying a registration fee. But formation is only the beginning. To operate properly, maintain legal protection, and meet the expectations of banks, payment processors, and investors, a US LLC needs a set of core business documents in place. Without them, you will encounter friction at nearly every subsequent step.
This guide explains each key document, what it does, and why it matters for non-resident founders. For the specific documents required to open a US bank account, see our banking documents checklist.
Why Business Documents Matter for an LLC
LLCs are known for their simplicity compared with corporations, but they still require proper documentation to function effectively. These documents establish the legal existence of the company, define ownership and management rights, and provide proof of legitimacy when dealing with banks, payment processors, suppliers, and investors. For foreign founders, business documentation also helps demonstrate that the company operates as a separate legal entity — distinct from the personal affairs of its owners. Maintaining this separation is critical for preserving the limited liability protection the LLC structure provides. Without it, that protection can be challenged.
Articles of Organization
The Articles of Organization are the official documents filed with the state government that legally create the LLC. Depending on the state, this document may be called the Certificate of Formation or Certificate of Organization — but regardless of name, it serves the same purpose: registering the company with the state. It records the legal name of the LLC, the registered agent's address, the state of formation, the principal business address, and whether the LLC will be member-managed or manager-managed.
Once approved and stamped by the state, the Articles of Organization confirm that your LLC legally exists. For non-resident founders, this is the primary proof of incorporation required when opening US business bank accounts or registering with financial platforms.
Operating Agreement
The Operating Agreement is the internal governance document of the LLC. Although not legally required by all states, it is strongly recommended for all LLCs — including single-member companies — and most banks and payment processors will ask for it as part of their KYC process. It covers ownership percentages, voting rights and decision-making processes, distribution of profits and losses, roles and responsibilities of members or managers, procedures for adding or removing members, and rules for dissolving the company.
For single-member LLCs, the Operating Agreement demonstrates that the business is being operated as a genuinely separate legal entity — reinforcing the liability protection the structure provides. Without one, a court or regulator may be less inclined to treat the LLC as truly separate from its owner. For UK and EU founders, the Operating Agreement is broadly comparable to a shareholders' agreement or company constitution under European corporate structures.
EIN Confirmation Letter (CP 575)
The Employer Identification Number is issued by the IRS and functions as the company's federal tax identification number — similar in concept to a UK company tax reference. Businesses need an EIN to open a US bank account, file tax documents with the IRS, hire US employees or contractors, and register with payment processors. Once issued, the IRS sends a CP 575 letter confirming the EIN. Keep the original CP 575 permanently and securely — banks require it as part of KYC, and replacing a lost confirmation requires contacting the IRS Business & Specialty Tax Line directly to request a 147C letter.
Membership Certificates
Membership certificates confirm ownership in the LLC — analogous to share certificates in a corporation, but for LLC membership interests. They provide written evidence that a specific person or organisation owns a stated percentage of the company. While not legally required in most states, membership certificates are valuable for record-keeping, for demonstrating ownership to banks or investors, and for formalising ownership arrangements in multi-member LLCs where disputes about percentage ownership can otherwise arise.
Company Resolutions
Company resolutions are formal written records of significant decisions made by the members or managers of the LLC — such as opening a bank account, entering a major contract, appointing or removing a manager, or changing the ownership structure. Banks and financial institutions frequently request a resolution authorising specific individuals to act on behalf of the company. Maintaining written resolutions also strengthens the legal separation between the company and its owners — an important safeguard for the LLC's liability protection.
Registered Agent Agreement
Every US LLC must appoint a registered agent in the formation state. The registered agent receives official legal and government documents on behalf of the company — including court notices and state compliance correspondence. Many registered agent services provide a written agreement confirming their appointment and responsibilities. This agreement demonstrates that the company has fulfilled its legal obligation to maintain a registered agent within the state — an obligation that must be maintained continuously, not just at formation.
Organising and Storing Your Company Records
LLCs should maintain a secure digital record of all key company documents: Articles of Organization, Operating Agreement, EIN confirmation, ownership records, resolutions, and compliance filings. For non-resident founders managing their company remotely, digital document storage is essential — ensuring all records are accessible from anywhere and immediately available when a bank, payment processor, or counterparty requests them. A structured digital folder organised by document type is sufficient; a complex system is not necessary.
Building a Solid Foundation
Key documents like the Articles of Organization, Operating Agreement, EIN confirmation, and membership records define how your company operates and provide the proof of legitimacy that banks, partners, and investors expect. Getting these in place from formation — rather than trying to rectify gaps later — saves significant time and avoids friction at every subsequent step.
We provide UK and European founders with all core LLC formation documents as part of our formation service, including operating agreements and EIN applications through our licensed Enrolled Agent Richard Williams.
US Banking Documents Checklist
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