Maine will not let you file your Certificate of Formation online. Every other step in this guide can happen from a laptop, but the document that actually creates your LLC has to go in the mail or get delivered in person, and that one quirk is why Maine formations often take 35 to 40 business days when most states take a few.
TL;DR
- No online filing: Maine's Certificate of Formation (Form MLLC-6) must be mailed or delivered in person, which is why standard processing runs roughly 35 to 40 business days.
- Expedited options exist: pay an extra $50 for next-business-day processing or $100 for same-business-day processing if the mail-only default is too slow.
- Registered agent required: a physical Maine street address, either a Maine resident or an authorized business entity, no PO box.
- EIN is free from the IRS: SSN/ITIN holders apply online, everyone else uses Form SS-4 by phone, fax, or mail.
- Foreign-owned single-member LLCs must file Form 5472: the penalty for missing it starts at $25,000, even at zero revenue.
- Annual Report is due June 1 every year: $85 for a domestic LLC, with a flat $50 late penalty starting June 2 and no grace period.
Why Form an LLC in Maine
Maine's LLC process follows the same basic shape as most states: pick a name, appoint a registered agent, file a formation document, then handle the ongoing federal and state obligations that come with running the entity. The paperwork itself isn't unusual.
What sets Maine apart is the filing method. The state has no online portal for the Certificate of Formation, so founders used to same-day approvals elsewhere need to plan around a mail-only process and a real waiting period. That timing detail shapes several of the steps below, particularly Step 3.
Step 1: Choose Your LLC Name
Your LLC's name has to contain "Limited Liability Company," "LLC," or "L.L.C." and be distinguishable from other business names already on file with the Maine Secretary of State.
- Check availability first. Search the state's business name database before you file anything to confirm the name isn't already taken.
- Reserve it if you're not ready to file. Form MLLC-1 holds a name for 120 days for a $20 fee.
- The reservation doesn't renew. Once the 120 days lapse, you have to file for formation or lose the name to someone else.
A name reservation buys time, but it's not a substitute for filing. Treat it as a placeholder while you line up the registered agent and formation paperwork in the next two steps.
Step 2: Appoint a Registered Agent
Maine requires every LLC to name a registered agent: an individual Maine resident or an authorized business entity with a physical street address in the state. A PO box alone doesn't satisfy the requirement.
The registered agent's job is to receive legal notices and state correspondence on the LLC's behalf during business hours. If you don't have a Maine address yourself, a commercial registered agent service fills that role.
This appointment gets listed directly on your Certificate of Formation in Step 3, so confirm the agent and address before you fill out that form. Changing it later means a separate filing.
Step 3: File Your Certificate of Formation
This is the filing that legally creates your LLC. Maine uses Form MLLC-6, and the filing fee is $175.
The mail-only filing process
Maine is unusual among states in that it offers no online filing for the Certificate of Formation. You have to mail the form or deliver it in person to the Secretary of State's office. There's no digital shortcut around it.
- Standard processing: roughly 35 to 40 business days is the typical range founders should plan around. This isn't a statutory deadline, so treat it as a planning estimate rather than a guarantee.
- Next-business-day expedite: add $50 to move the filing to the front of the queue.
- Same-business-day expedite: add $100 if you need the LLC formed immediately.
Maine has no publication requirement, which is one less step compared to states like New York or Arizona. But the mail-only process makes the expedite fees genuinely worth considering if a bank account, contract, or investor deadline depends on having the LLC formed by a specific date.
Step 4: Apply for Your EIN
An Employer Identification Number (EIN) is what the IRS uses to identify your LLC for tax purposes, and you'll need one to open a US bank account or file federal taxes. It's free directly from the IRS.
- SSN or ITIN holders can apply online and typically receive the EIN the same day.
- Founders without an SSN or ITIN apply using Form SS-4 by phone, fax, or mail instead, since the online tool isn't available to them.
Apply for the EIN only after your Certificate of Formation is approved. The IRS ties the EIN to a legally formed entity, so applying earlier just means resubmitting later.
Step 5: File Form 5472 if the LLC Is Foreign-Owned
If your single-member LLC is 25% or more foreign-owned, the IRS requires an annual Form 5472 filing, even at zero revenue. It's filed alongside a pro forma Form 1120, a placeholder corporate return required for the submission even though the LLC itself owes no separate corporate tax.
The minimum penalty for a late or missing Form 5472 is $25,000, per form, per year. Founders who assume a dormant or low-activity LLC has nothing to report are exactly who this catches, since the requirement applies regardless of profitability.
This filing obligation starts the moment your foreign-owned LLC exists, not once it starts generating revenue. Treat it as a fixed annual task from day one.
Step 6: Handle Ongoing Compliance
Maine LLCs have two recurring obligations worth tracking from the start: the Annual Report and state income tax.
Annual Report
- Due June 1 every year for domestic LLCs, with an $85 filing fee.
- Can be filed online, unlike the Certificate of Formation itself.
- Late penalty is a flat $50, applying starting June 2 with no grace period, bringing the total to $135 if you miss the deadline.
Maine state income tax
Maine uses a graduated state income tax with three brackets, topping out at 7.15% for 2026. For single filers and those married filing separately:
| Taxable income | Rate |
|---|---|
| Under $27,400 | 5.8% |
| $27,400 to $64,850 | $1,589 plus 6.75% of the amount over $27,400 |
| Over $64,850 | $4,117 plus 7.15% of the amount over $64,850 |
Income over $500,000 carries an additional 3% surcharge on top of the bracket rate. This is general information, not tax advice, and your actual liability depends on your full financial picture, so consult a tax professional for individual guidance.
If you plan to register the LLC to do business in another state, Maine also offers a Statement of Foreign Qualification to Conduct Business Activities, with a fee that's approximately $250. That figure isn't fully confirmed against a primary source, so verify it directly with the Secretary of State before budgeting around it.
Common Mistakes to Avoid
- Assuming Maine has online formation filing. Planning a formation timeline around another state's instant online process will leave you scrambling when the Certificate of Formation has to go in the mail.
- Skipping the expedite fee when timing matters. The 35-40 business day baseline is long enough to delay a bank account or contract; the $50 or $100 expedite is often worth it.
- Missing the June 1 Annual Report deadline. The $50 penalty applies the very next day with no grace period, so this isn't a date to treat loosely.
- Treating Form 5472 as optional at zero revenue. The $25,000 minimum penalty applies whether or not the LLC made a dollar.
- Using a non-qualifying address for the registered agent. A PO box alone doesn't meet Maine's physical-address requirement.
How FinStackk Helps With Starting Your LLC in Maine
FinStackk is an accounting and tax compliance platform for U.S. businesses, helping you go from incorporation to ongoing accounting, tax, and compliance, all in one place.
We handle the incorporation steps above, including EIN applications and registered agent service, through Fin-Start. Once your LLC exists, Fin-Tax keeps ongoing filings, including Form 5472 and Maine's Annual Report, on a proactive deadline calendar instead of leaving you to track them yourself. Book a free demo to see both in action.
FAQ
Why can't I file my Maine LLC formation online?
Maine's Secretary of State doesn't offer an online filing option for the Certificate of Formation (Form MLLC-6). You have to mail it in or deliver it in person, which is unusual compared to most other states. This is also why standard processing typically runs 35 to 40 business days rather than the same-day or next-day turnaround common elsewhere, though founders in a hurry can pay $50 for next-business-day processing or $100 for same-business-day processing.
How much does it cost to start an LLC in Maine?
The Certificate of Formation filing fee is $175. If you want to reserve your name before filing, that's an additional $20 for Form MLLC-1. A registered agent service, if you need one, typically adds an annual cost on top. The EIN itself is free directly from the IRS regardless of which route you use to apply.
What happens if I miss Maine's Annual Report deadline?
Maine's Annual Report is due June 1 every year, with an $85 fee for a domestic LLC. If it's not filed by then, a flat $50 late penalty applies starting June 2, with no grace period, bringing the total due to $135. The report can be filed online, which is different from the mail-only Certificate of Formation process.