Skip to main content
FormifyAI
PricingStatesGuidesBlog
(978) 321-0417Sign InGet Started
SOC 2 Compliant
256-bit SSL
4.9/5 rated
All 50 states
FormifyAI

Form your LLC in any U.S. state with a flat monthly plan. Registered agent, operating agreement, EIN filing, and compliance tracking — all included. No surprise upsells.

support@formifyai.app
(978) 321-0417
4.9· 150+ LLCs filed

Product

  • LLC Formation
  • Registered Agent
  • EIN Application
  • Annual Reports
  • Add-ons
  • Pricing

Resources

  • LLC Guides
  • Blog
  • LLC by State
  • LLC by Industry
  • Compare
  • LLC Name Tool

Company

  • About
  • Careers
  • Contact
  • Investors
  • Help Center
  • Affiliate Program

From the same team

InsurifyAI

Business insurance marketplace

DisputeAI

AI credit dispute letters

Pointify Travels

Business travel + points

SubScrub

Subscription management

DebtShield

Debt collection letter review

Not a law firm. FormifyAI is not a law firm or substitute for an attorney. We provide business formation filing services and document preparation self-help. Information on this site is for general informational purposes only and does not constitute legal advice. For questions about your specific situation, please consult a qualified attorney.

© 2026FormifyAI. A product of InsurifyAI LLC · Nashua, NH

Registered Agent: 221 Main St, Ste A, Nashua, NH 03060

PrivacyTermsRefundsCookies
catch us if you can
  1. Help
  2. /
  3. Compliance
Compliance

How to add a co-founder to my LLC

Adding a member is a state filing — usually called an Amendment. FormifyAI handles the paperwork; you handle the operating agreement update.

3 min·Updated Apr 27, 2026

Adding a co-founder turns your single-member LLC into a multi-member LLC. There are three things that change: the state filing, the operating agreement, and your IRS classification.

1. The state filing

Most states require an Amendment to your Articles of Organization adding the new member. Some states (NH, MA) don't require it because members aren't listed publicly. Open your entity in the dashboard and pick Amendment → Add Member; we'll generate the right filing for your state.

2. Operating agreement update

Update your operating agreement with: the new member's ownership %, capital contribution, voting rights, and how distributions split. This is internal — you don't file it with the state, but every member must sign.

3. IRS classification change

Single-member LLCs are taxed as sole props by default. The moment you have two members, the IRS treats you as a partnership and you must file Form 1065 (partnership return) annually. Tell your accountant — and consider whether S-Corp election makes sense at the new income level.

Don't forget the EIN: if your single-member LLC didn't have one, you'll need one now (multi-member LLCs require an EIN). We can file the SS-4 for you — it's free.

Was this article helpful?

If you still have questions, email our team — real humans answer in under an hour.

Related articles

  • How to change my registered agent3 min
  • When is my annual report due?2 min
  • Will my LLC need an operating agreement?3 min
Back to Help center