Maine is one of the last states where you can't file your LLC formation paperwork online. The Certificate of Formation has to be mailed or hand-delivered to the Secretary of State's office in Augusta, which adds a few extra days to a process that's instant in most other states. Here's what it takes to start a business in Maine in 2026.
1. Which business structure fits you?
Before you file anything, it helps to know what you're actually choosing between.
- Sole proprietorship. No filing required to start, and you and the business are legally the same entity. Simple, but you're personally liable for whatever the business owes.
- Partnership. Two or more people running a business together, with the same liability exposure as a sole proprietorship, just split across partners.
- LLC. The most common structure for small businesses in Maine. It separates your personal assets from the business's debts and lawsuits.
- Corporation, either S-corp or C-corp. More paperwork and more formality, usually worth it once you're bringing on investors or multiple shareholders.
For a deeper comparison, see our guide on choosing a business structure.
LLCs and corporations register with the Maine Secretary of State, Bureau of Corporations, Elections and Commissions, the agency that handles business filings statewide. Sole proprietorships and general partnerships don't register there.
2. Register your business
Forming an LLC
You form an LLC in Maine by filing a Certificate of Formation (Form MLLC-6) with the Secretary of State. The filing fee is $175, and since Maine only accepts mail or in-person filings for this document, standard processing runs 5 to 10 business days plus mail transit time. Expedited options are available for an extra $50 (next business day) or $100 (same day).
Every LLC needs a registered agent with a physical Maine address, available during business hours. You can act as your own agent, or hire a commercial service.
Maine doesn't require an operating agreement by law, but it's still worth writing one, particularly for multi-member LLCs, to spell out how decisions and profits get split.
Sole proprietorships and DBAs
Sole proprietorships don't file a Certificate of Formation. If you're operating under a trade name, you'll register it at the municipal level where your business is located.
3. Get an EIN
An Employer Identification Number is free straight from the IRS and takes about 15 minutes online. You'll need one to open a business bank account, hire anyone, or file most business tax forms, even if you're a single-member LLC with no employees.
4. Check licenses and permits
Maine doesn't issue a single general statewide business license either. What you need depends on your industry and city: professional licensing for regulated fields, local permits in some municipalities, and a free Retailer Certificate from Maine Revenue Services if you sell taxable goods or services. Our guides on professional licensing by industry and zoning laws for home businesses cover more of this.
5. Understand Maine taxes
Maine has a progressive personal income tax for 2026: 5.8% on income up to roughly $27,400, 6.75% from there to about $64,850, and 7.15% above that for single filers. Pass-through LLCs owe no separate franchise tax; if you elect corporate treatment, Maine's corporate income tax is graduated from 3.5% up to 8.93%.
Sales tax is a flat 5.5% statewide, and Maine doesn't allow local add-ons, so the rate is the same everywhere. A separate 6% Service Provider Tax applies to a narrow list of specific services like telecommunications and cable, but most professional and personal services aren't affected.
6. Stay compliant
Every Maine LLC files an Annual Report with the Secretary of State, due by June 1 each year, starting the year after formation. The fee is $85 for domestic LLCs. The filing window opens January 1, giving you a five-month runway. Missing the deadline can trigger a $50 late penalty and eventual administrative dissolution.
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 options available for an extra $50 or $100.
What's the personal income tax rate in Maine?
Progressive for 2026, 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 applies to a narrow list of services.
When is Maine's Annual Report due?
By June 1 each year, starting the year after formation, for $85.
Fees and rates above come from the Maine Secretary of State and Maine Revenue Services as of 2026, and they do change over time, so double check before you file. None of this is legal or tax advice. Talk to a Maine-licensed attorney or CPA about your specific situation.