Maine is one of the last states where LLC formation paperwork can't be filed online. The Certificate of Formation has to be mailed or hand-delivered to the Secretary of State's office in Augusta, adding a few extra days to a process that's instant almost everywhere else. What follows covers the full process of starting a business in Maine in 2026.
1. Which business structure fits you?
The legal structure you pick shapes everything else that follows, so start there.
- Sole proprietorship. You're the business, legally speaking. Nothing to file to start, but nothing shielding your personal assets either.
- Partnership. Same personal liability as a sole proprietorship, just shared between two or more owners.
- LLC. Maine's most popular pick for small operations, mainly because it separates what you own personally from what the business owes.
- Corporation, S-corp or C-corp. Comes with more paperwork and formal upkeep, generally justified once you bring on investors or several shareholders.
See our guide to choosing a business structure for a closer look at the tradeoffs.
The Maine Secretary of State's Bureau of Corporations, Elections and Commissions is where LLCs and corporations register; sole proprietorships and general partnerships have nothing to file there.
2. Register your business
Forming an LLC
Maine LLCs form by filing a Certificate of Formation, Form MLLC-6, with the Secretary of State, and the fee runs $175. Because this particular filing can't be done online, mail or in-person only, plan on 5 to 10 business days of processing on top of however long the mail takes. Paying an extra $50 buys next-business-day handling, and $100 gets it done the same day.
A registered agent with a physical Maine address is required for every LLC, and they need to be available during business hours. That can be you or a paid service.
Maine has no legal requirement for an operating agreement, but multi-member LLCs in particular benefit from putting one together anyway, since it settles decision-making and profit-sharing before disagreements arise.
Sole proprietorships and DBAs
No Certificate of Formation is needed for a sole proprietorship. Trade name registration, if you need it, happens at the municipal level, in the town or city where you operate.
3. Get an EIN
An Employer Identification Number is a free 15-minute application on the IRS site. You'll be asked for it when opening a business bank account, hiring anyone, or filing most tax forms, even for a solo-owner LLC with no staff.
4. Check licenses and permits
Maine skips a general statewide license too, so what you need hinges on industry and location: professional licensing in regulated fields, local permits in some municipalities, and a free Retailer Certificate from Maine Revenue Services for anyone selling taxable goods or services. Our guides on professional licensing by industry and zoning for home-based businesses cover more ground here.
5. Understand Maine taxes
Maine taxes personal income progressively in 2026: 5.8% up to about $27,400, 6.75% on the next bracket up to roughly $64,850, and 7.15% beyond that, for single filers. No separate franchise tax applies to pass-through LLCs. Electing corporate treatment instead brings a graduated corporate income tax ranging from 3.5% to 8.93%.
The sales tax rate holds at a flat 5.5% everywhere in the state, with no local add-ons permitted. A distinct 6% Service Provider Tax hits a narrow category of services, telecommunications and cable among them, though it leaves most professional and personal services untouched.
6. Stay compliant
Starting the year after you form, Maine LLCs owe an Annual Report to the Secretary of State by June 1, at a cost of $85 for domestic entities. The window opens January 1, so you get about five months to file. Blow the deadline and a $50 late penalty follows, with administrative dissolution a possibility down the line.
Maine business costs at a glance
| Item | Cost |
|---|---|
| Certificate of Formation (LLC, mail-only) | $175 |
| Annual Report (every year, due June 1) | $85 |
| Late penalty | $50 |
| Registered agent service (optional) | $150 to $200/year |
| EIN | Free (IRS) |
| State income tax | 5.8% to 7.15% (progressive) |
| State sales tax | 5.5% flat, no local add-on |
Frequently asked questions
Can I form an LLC in Maine entirely online?
No. Maine only accepts mail or in-person filings for the Certificate of Formation, one of the last states with that restriction.
How much does it cost to form an LLC in Maine?
$175 for the Certificate of Formation, with expedited processing available for an extra $50 or $100.
What's the personal income tax rate in Maine?
Progressive for 2026, running from 5.8% up to 7.15% for single filers depending on income.
Does sales tax vary by city in Maine?
No. It's a flat 5.5% statewide with no local add-ons, though a separate 6% Service Provider Tax covers a narrow list of services.
When is Maine's Annual Report due?
By June 1 each year, starting the year after formation, for $85.
Figures throughout come from the Maine Secretary of State and Maine Revenue Services as of 2026, and they're subject to revision, so confirm details before filing. Nothing here constitutes legal or tax advice; talk to a Maine-licensed attorney or CPA about your particular situation.