US Company Setup Checklist: What Every New LLC or Corporation Must Do After Formation

Setting up a US company—whether an LLC or a Corporation (C-Corp or S-Corp)—does not end once the state approves your formation documents. In practice, post-incorporation compliance is where most founders face delays, banking rejections, tax notices, and operational risks.

This guide provides a clear, authoritative checklist covering what every new US company must complete after formation, including EIN registration, banking, internal agreements, tax setup, and ongoing compliance. It is written for US and non-US founders seeking accurate, practical guidance.

Why Post-Incorporation Steps Are Critical

Skipping or delaying post-formation requirements can result in:

• IRS penalties and compliance notices

• Inability to open a US bank account or onboard payment processors

• Loss of limited liability protection

• Issues with investors, partners, or future exits

A structured checklist ensures your US company is legally compliant, bank-ready, and operational from day one.

Step 1: Obtain an EIN (Employer Identification Number)

An EIN (Employer Identification Number) is the federal tax ID issued by the Internal Revenue Service (IRS) and is required for most US business operations.

Why an EIN Is Essential

• Opening a US business bank account

• Filing federal and state tax returns

• Hiring employees or paying contractors

• Using payment processors such as Stripe, PayPal, or Amazon

Even companies with no revenue or activity often still need an EIN for compliance and banking purposes.

You can verify official EIN requirements directly with the IRS here: Internal Revenue Service (IRS) – Employer Identification Numbers (EIN)

Step 2: Open a US Business Bank Account

Every US LLC or Corporation should maintain a separate business bank account to preserve legal and financial separation from its owners.

Common Bank Requirements

• Certificate of Formation / Incorporation

• EIN confirmation letter

• Operating Agreement (LLC) or Bylaws (Corporation)

• Identification documents of owners/directors

• Registered US business address

Mixing personal and business funds can expose owners to loss of limited liability and tax complications.

Step 3: Prepare Internal Governance Documents

Internal governance documents are essential even if they are not filed with the state.

For LLCs: Operating Agreement

An Operating Agreement defines:

• Ownership and profit allocation

• Management authority

• Voting rights and dispute resolution

Banks, investors, and the IRS frequently request this document.

For Corporations: Bylaws & Shareholder Records

Corporations must maintain:

• Corporate bylaws

• Shareholder and director resolutions

• Stock issuance records and cap table

Without proper governance documents, a company may be treated as non-compliant or improperly structured.

Step 4: Register for Federal, State, and Local Taxes

Federal Tax Setup

• Confirm IRS tax classification (default or elected)

• File required forms for foreign-owned entities (where applicable)

• Plan estimated tax obligations

State & Local Registrations

Depending on business activity:

• Franchise or state income tax registration

• Sales tax permits

• Payroll tax registration (if hiring employees)

Tax obligations vary by state, activity, and ownership structure, making early planning essential.

Step 5: Maintain a Registered Agent

All US companies must appoint and maintain a registered agent in their state of incorporation.

The registered agent:

• Receives legal notices and government correspondence

• Ensures timely handling of compliance documents

Failure to maintain a registered agent can lead to loss of good standing or administrative dissolution.

Step 6: Set Up Accounting, Bookkeeping, and Recordkeeping

From the first day of operation, US companies are expected to maintain accurate financial records.

Best practices include:

• Selecting an accounting method (cash or accrual)

• Maintaining organized income and expense records

• Retaining contracts, invoices, and receipts

Proper bookkeeping supports tax filings, audits, investor due diligence, and future fundraising.

Step 7: Obtain Business Licenses and Permits (If Applicable)

Not all US businesses require licenses, but many do depending on:

• Business activity

• State and city of operation

• Industry regulations

The US Small Business Administration (SBA) provides official guidance on licensing requirements across federal, state, and local levels: US Small Business Administration – Apply for Licenses and Permits

Step 8: Fulfill Annual and Ongoing Compliance Obligations

After setup, compliance becomes an ongoing responsibility.

Typical requirements include:

• State annual reports

• Franchise or annual state taxes

• Federal and state tax filings

• Maintaining good standing with authorities

Missing deadlines may result in penalties, interest, or forced dissolution.

Common Mistakes New US Company Owners Make

• Assuming formation alone is sufficient

• Delaying EIN or banking setup

• Operating without internal agreements

• Ignoring tax registrations and filings

• Mixing personal and business finances

These errors are common—and entirely preventable with proper guidance.

How Mirr Asia Supports US Companies After Formation

Mirr Asia Business Advisory assists founders beyond incorporation, including:

• EIN registration for US and non-US owners

• US bank and EMI account coordination

• Operating Agreements and corporate governance setup

• Federal and state tax registration guidance

• Ongoing compliance and annual filing support

Our focus is ensuring your US company is compliant, operational, and scalable from the start.

Final Thoughts

Forming a US company is only the beginning. Completing post-incorporation steps correctly ensures your business is legally protected, bank-ready, and positioned for growth.

For founders seeking a fully managed, compliant US company setup, Mirr Asia provides end-to-end advisory support with accuracy and professionalism.

Frequently Asked Questions (FAQs)

1. Do I need an EIN if my US company has no income?

Yes. An EIN is required for banking, tax filings, and compliance, even if the company has no revenue or transactions.

2. Can a non-US resident open a US company bank account?

Yes. Non-US residents can open US business bank accounts, but banks require additional documentation and compliance checks.

3. Is an Operating Agreement mandatory for a US LLC?

While not always filed with the state, an Operating Agreement is legally essential and required by banks, the IRS, and investors.

4. What happens if post-incorporation compliance is ignored?

Ignoring compliance can lead to IRS penalties, bank account rejection, loss of good standing, and potential loss of limited liability protection.

5. How soon should post-formation steps be completed?

Ideally, all critical post-incorporation steps should be completed within 30 days of formation.