Can a sole proprietor convert to an LLC in Montana?

Yes. A sole proprietorship is not a legal entity separate from its owner, so you convert by forming a new Montana LLC and moving the business into it. File Articles of Organization online with the Montana Secretary of State and pay the $35 filing fee. On the EIN, the IRS says a single-member LLC can keep using your sole proprietor EIN if it does not choose corporate or S-Corporation tax treatment, has no employees and owes no excise tax; otherwise it needs its own EIN, which you apply for on Form SS-4. Update your business licenses, bank accounts and contracts so they name the LLC, and check whether any state tax registrations must be reissued in the LLC's name. Forming the LLC gives you limited liability protection that a sole proprietorship lacks. File your Articles of Organization online through the Montana Secretary of State to get started.

Does forming an LLC in Montana reduce self-employment tax?

No, forming a Montana LLC doesn't by itself reduce self-employment tax. By default, a single-member LLC is taxed like a sole proprietorship and a multi-member LLC like a partnership, and the owners generally owe 15.3% self-employment tax on net self-employment earnings. Self-employment tax is a federal tax paid to the IRS, not to the Montana Department of Revenue: it is 12.4% for Social Security, which applies only up to an annual earnings cap, plus 2.9% for Medicare. However, an eligible LLC can file Form 2553 (Election by a Small Business Corporation) with the IRS to be taxed as an S-Corporation. You then pay yourself a reasonable salary, which is subject to Social Security and Medicare payroll taxes, and take remaining profits as distributions, which are not. The trade-off: an S-Corporation must run payroll, file payroll tax returns and a separate federal return (Form 1120-S), and pay for the accounting that requires. Whether the tax savings exceed those costs depends on your profits. Next step: consult a Montana CPA to model the savings based on your projected income before filing Form 2553.

How much does it cost to form an LLC in Montana?

The Montana Secretary of State charges $35 to file Articles of Organization, and filing is online only, through the biz.sosmt.gov portal; a series LLC pays an extra $50 for each series named. The Secretary of State does not publish a standard turnaround time, but sells 24-hour priority handling for $20 and 1-hour expedite for $100. Starting the year after the LLC is organized, it files an annual report between January 1 and April 15; the Secretary of State waives the $20 fee for 2026 and 2027 reports filed in that window, and a report filed after April 15 costs $35. Montana imposes no franchise tax on a default LLC. Every Montana LLC must name a registered agent. If you use a paid formation service, Northwest Registered Agent charges $39 plus state fees with a year of registered agent service included (then $125 a year), and ZenBusiness charges $0 plus state fees, with registered agent service at $99 for the first year when you form with them (then $199 a year). File your Articles of Organization online through the Montana Secretary of State to get started.

Does an LLC protect personal assets in Montana?

Yes. Under MCA 35-8-304(1), a member or manager of a Montana LLC is not liable, solely by reason of being a member or manager, for a debt, obligation or liability of the LLC, whether arising in contract, tort or otherwise, subject to the exceptions the statute lists, such as members who consent in writing to a provision in the articles making them liable (subsection (3)). That protection has limits: it covers liability that arises only from your role as a member or manager, so it does not cover, for example, a debt you personally guarantee. Montana law also says that an LLC's failure to observe the usual company formalities is not a ground for imposing personal liability on its members or managers (MCA 35-8-304(2)), so skipping meetings or minutes is not by itself a reason to lose your protection. Keeping a separate business bank account and never mixing personal and business funds are still sensible practices, because courts can in some cases disregard an LLC and reach its owners ("piercing the veil"), and commingled funds invite that argument. If a creditor wins a judgment against your LLC for a company obligation you did not guarantee, it generally collects from the LLC's assets, not your personal home and savings. To secure this protection, file your Articles of Organization with the Montana Secretary of State and open a dedicated business bank account from day one.

Can one person own an LLC in Montana?

Yes, Montana allows single-member LLCs owned and controlled by one person, who can also manage the company. For federal tax purposes, the IRS treats a single-member LLC as a disregarded entity by default, so the LLC's income is reported on your personal return, just as with a sole proprietorship. An eligible LLC can instead elect S-Corporation tax treatment by filing Form 2553 with the IRS, which can reduce self-employment taxes on profits taken as distributions. The practical benefit: you gain personal liability protection for business debts while keeping tax filing simple. Montana's filing fee is $35 for the Articles of Organization, and the annual report fee is waived for 2026 and 2027 reports filed between January 1 and April 15 ($20 otherwise when filed on time). Next step: file your Articles of Organization with the Montana Secretary of State, then open a business bank account to keep business and personal finances separate. The IRS says a single-member LLC with no employees, no excise tax and no corporate tax election can use your sole proprietor EIN instead of getting a new one.

Is a sole proprietorship legal in Montana without registration?

Yes, sole proprietorships don't require state registration in Montana. You become a sole proprietor the moment you start doing business, with no formation filing with the Montana Secretary of State. There are still caveats. If you do business under an assumed business name, MCA 30-13-203 requires you to register it with the Montana Secretary of State. Check with your city or county whether your type of business needs a local license, since local requirements and fees vary, and certain professions need a state license from their licensing board. The practical implication: while you avoid LLC filing fees, you remain personally liable for all business debts and legal judgments, unlike an LLC owner. Your next step: contact your city or county to confirm licensing requirements and fees for your specific business type and location.

LLC Guide

Montana LLC vs Sole Proprietorship: Complete 2026 Comparison

Discover which business structure offers the best protection, tax advantages, and growth potential for your Montana business venture.

Last updated: September 2026

In Montana, an LLC fits when your business faces potential liability risks from customers, employees, or professional services; a sole proprietorship fits when you're testing a low-risk business idea with minimal startup costs. Compare both structures in detail below.

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Comparison chart for Montana LLC versus Sole Proprietorship, contrasting liability, taxation and ongoing filing burden across 8 factors. — Side-by-side on the factors that decide the choice, for Montana. Source: Montana Secretary of State.

LLC vs Sole Proprietorship: Side-by-Side

Factor	LLC	Sole Proprietorship
Personal liability protection	Limited liability: members are not personally liable for the LLC's debts and obligations solely because they are members	No protection: you're personally liable for all business debts and legal claims
Formation cost & paperwork	$35 Montana filing fee for Articles of Organization, filed online with the Secretary of State	No state formation filing required, just start doing business
Taxation	Pass-through by default (no double taxation), with the option to elect corporate or S-Corporation tax treatment	Pass-through only: all business income is reported on your personal return (Schedule C)
Self-employment tax	15.3% self-employment tax on net self-employment earnings by default (Social Security part capped yearly); an S-Corp election may reduce it at higher profits	15.3% self-employment tax on net self-employment earnings, with the Social Security part capped each year; a sole proprietorship cannot elect S-Corp status
Business credibility	Professional appearance with 'LLC' designation helps with customers, vendors, and lenders	May appear less established: operates under your personal name or a trade name
Banking & contracts	Separate business bank account recommended to keep LLC and personal funds apart; easier to get business credit cards and loans	Can use personal accounts, though a separate account makes business records and taxes easier to track
State fees in Montana	$35 one-time filing fee; the annual report fee is waived for 2026 and 2027 reports filed January 1 to April 15, is otherwise $20 when filed on time, and is $35 after April 15	$0 in state formation fees; registering an assumed business name with the Secretary of State is required if you trade under one
Conversion path to LLC	Already an LLC: can elect different tax treatments as the business grows	You can form a Montana LLC later by filing Articles of Organization with the Secretary of State

When an LLC Makes More Sense

Your business faces potential liability risks from customers, employees, or professional services
You want to build business credit separate from your personal credit profile
You plan to have business partners or investors join your venture
Your profits are high enough that an S-Corp election's self-employment tax savings would outweigh the added payroll and accounting costs

When a Sole Proprietorship Makes More Sense

You're testing a low-risk business idea with minimal startup costs
Your business has low liability exposure and minimal regulatory requirements
You want the simplest possible business structure with no annual report
Your income is modest and you want maximum tax simplicity

Tax Deep Dive

Sole Prop Tax

Sole proprietorships report business income on Schedule C of your personal federal return. You pay regular income tax plus 15.3% self-employment tax on net self-employment earnings, with the 12.4% Social Security part applying only up to an annual earnings cap, and a sole proprietorship cannot elect S-Corporation tax treatment. Montana also taxes that profit at its individual income tax rates of 4.7% and 5.65% for 2026.

Llc Default Tax

By default, a single-member LLC is a 'disregarded entity' for federal tax purposes, taxed like a sole proprietorship, and a multi-member LLC is taxed as a partnership. Either way, you generally still owe self-employment tax on net self-employment earnings, but an LLC can elect a different tax treatment as your business grows. Montana imposes no franchise or minimum entity tax on an LLC left in its default classification.

Llc S Corp Election

Montana LLCs can elect S-Corporation tax status with the IRS to split income into a reasonable salary (subject to Social Security and Medicare payroll taxes) and distributions (not subject to those taxes). Whether it saves money depends on your profits and the added payroll and accounting costs, so have a CPA model it before electing.

This guide is general information, not legal or tax advice, and reading it does not create an attorney-client relationship. It reports published tax rates and statutory attributes, with the sources this page cites. It cannot tell you which structure is better for you: that turns on your profit, the salary you could defend as reasonable compensation, every state you owe tax in, and plans for owners, investors and exit that no figure on this page measures. Confirm your own position with a CPA or tax attorney licensed in your state before you elect anything, because some elections are slow or costly to reverse.

Frequently Asked Questions

: Yes. A sole proprietorship is not a legal entity separate from its owner, so you convert by forming a new Montana LLC and moving the business into it. File Articles of Organization online with the Montana Secretary of State and pay the $35 filing fee. On the EIN, the IRS says a single-member LLC can keep using your sole proprietor EIN if it does not choose corporate or S-Corporation tax treatment, has no employees and owes no excise tax; otherwise it needs its own EIN, which you apply for on Form SS-4. Update your business licenses, bank accounts and contracts so they name the LLC, and check whether any state tax registrations must be reissued in the LLC's name. Forming the LLC gives you limited liability protection that a sole proprietorship lacks. File your Articles of Organization online through the Montana Secretary of State to get started.
: No, forming a Montana LLC doesn't by itself reduce self-employment tax. By default, a single-member LLC is taxed like a sole proprietorship and a multi-member LLC like a partnership, and the owners generally owe 15.3% self-employment tax on net self-employment earnings. Self-employment tax is a federal tax paid to the IRS, not to the Montana Department of Revenue: it is 12.4% for Social Security, which applies only up to an annual earnings cap, plus 2.9% for Medicare. However, an eligible LLC can file Form 2553 (Election by a Small Business Corporation) with the IRS to be taxed as an S-Corporation. You then pay yourself a reasonable salary, which is subject to Social Security and Medicare payroll taxes, and take remaining profits as distributions, which are not. The trade-off: an S-Corporation must run payroll, file payroll tax returns and a separate federal return (Form 1120-S), and pay for the accounting that requires. Whether the tax savings exceed those costs depends on your profits. Next step: consult a Montana CPA to model the savings based on your projected income before filing Form 2553.
: The Montana Secretary of State charges $35 to file Articles of Organization, and filing is online only, through the biz.sosmt.gov portal; a series LLC pays an extra $50 for each series named. The Secretary of State does not publish a standard turnaround time, but sells 24-hour priority handling for $20 and 1-hour expedite for $100. Starting the year after the LLC is organized, it files an annual report between January 1 and April 15; the Secretary of State waives the $20 fee for 2026 and 2027 reports filed in that window, and a report filed after April 15 costs $35. Montana imposes no franchise tax on a default LLC. Every Montana LLC must name a registered agent. If you use a paid formation service, Northwest Registered Agent charges $39 plus state fees with a year of registered agent service included (then $125 a year), and ZenBusiness charges $0 plus state fees, with registered agent service at $99 for the first year when you form with them (then $199 a year). File your Articles of Organization online through the Montana Secretary of State to get started.
: Yes. Under MCA 35-8-304(1), a member or manager of a Montana LLC is not liable, solely by reason of being a member or manager, for a debt, obligation or liability of the LLC, whether arising in contract, tort or otherwise, subject to the exceptions the statute lists, such as members who consent in writing to a provision in the articles making them liable (subsection (3)). That protection has limits: it covers liability that arises only from your role as a member or manager, so it does not cover, for example, a debt you personally guarantee. Montana law also says that an LLC's failure to observe the usual company formalities is not a ground for imposing personal liability on its members or managers (MCA 35-8-304(2)), so skipping meetings or minutes is not by itself a reason to lose your protection. Keeping a separate business bank account and never mixing personal and business funds are still sensible practices, because courts can in some cases disregard an LLC and reach its owners ("piercing the veil"), and commingled funds invite that argument. If a creditor wins a judgment against your LLC for a company obligation you did not guarantee, it generally collects from the LLC's assets, not your personal home and savings. To secure this protection, file your Articles of Organization with the Montana Secretary of State and open a dedicated business bank account from day one.
: Yes, Montana allows single-member LLCs owned and controlled by one person, who can also manage the company. For federal tax purposes, the IRS treats a single-member LLC as a disregarded entity by default, so the LLC's income is reported on your personal return, just as with a sole proprietorship. An eligible LLC can instead elect S-Corporation tax treatment by filing Form 2553 with the IRS, which can reduce self-employment taxes on profits taken as distributions. The practical benefit: you gain personal liability protection for business debts while keeping tax filing simple. Montana's filing fee is $35 for the Articles of Organization, and the annual report fee is waived for 2026 and 2027 reports filed between January 1 and April 15 ($20 otherwise when filed on time). Next step: file your Articles of Organization with the Montana Secretary of State, then open a business bank account to keep business and personal finances separate. The IRS says a single-member LLC with no employees, no excise tax and no corporate tax election can use your sole proprietor EIN instead of getting a new one.
: Yes, sole proprietorships don't require state registration in Montana. You become a sole proprietor the moment you start doing business, with no formation filing with the Montana Secretary of State. There are still caveats. If you do business under an assumed business name, MCA 30-13-203 requires you to register it with the Montana Secretary of State. Check with your city or county whether your type of business needs a local license, since local requirements and fees vary, and certain professions need a state license from their licensing board. The practical implication: while you avoid LLC filing fees, you remain personally liable for all business debts and legal judgments, unlike an LLC owner. Your next step: contact your city or county to confirm licensing requirements and fees for your specific business type and location.

Sources

Each entry below is a document recorded in our verified Montana sources, and each entry says what the document is. Some statutory text is read from an accurate mirror rather than from the state's own host, and those say so.

sosmt.gov/business/Montana Secretary of State: business entity filings
sosmt.gov/business/fees/Montana LLC filing fees

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