An Ohio single-member LLC is a disregarded entity by default, so the LLC itself files no income tax return; instead, the Ohio single-member LLC tax filing requirements run through the owner’s personal returns at three levels: federal (Form 1040 with Schedule C and Schedule SE), Ohio (IT 1040 with the Schedule of Business Income), and municipal (a net profit return in each city where the business has nexus). A separate Commercial Activity Tax applies at the entity level, but only if Ohio gross receipts exceed $6 million. Quarterly estimated payments are usually required at all three levels because nothing withholds tax from your business earnings.
Federal Filing: Schedule C, Self-Employment Tax, and Estimates
The IRS classifies a single-member LLC as a disregarded entity, which means the LLC files no federal income tax return of its own. Business revenue and expenses belong to you personally and go on Schedule C attached to your Form 1040. The net profit or loss from Schedule C flows into your adjusted gross income.1Internal Revenue Service. Single Member Limited Liability Companies2Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship)
That Schedule C profit is also subject to self-employment tax, which covers your Social Security and Medicare contributions. The combined rate is 15.3%: 12.4% for Social Security on earnings up to the annual wage base, plus 2.9% for Medicare on all net earnings. You calculate it on Schedule SE and pay it with your regular income tax.3Internal Revenue Service. About Schedule SE (Form 1040) – Self-Employment Tax
Because no one is withholding tax from your business income, you almost certainly owe quarterly estimated payments. Federal estimates are required if you expect to owe $1,000 or more after withholding and credits. You pay them with Form 1040-ES on the standard schedule: April 15, June 15, September 15, and January 15 of the following year.4Internal Revenue Service. Form 1040-ES – Estimated Tax for Individuals
When You Need an EIN
A single-member LLC with no employees and no excise tax liability can use the owner’s Social Security number for federal tax purposes. You must obtain an EIN if the LLC has employees or files excise tax returns. Even when it isn’t required, most banks want an EIN before they’ll open a business account, and using one keeps your Social Security number off vendor paperwork. The IRS issues EINs for free through its website.1Internal Revenue Service. Single Member Limited Liability Companies
Ohio IT 1040 and the Business Income Deduction
Ohio follows the federal treatment, so your Schedule C net profit flows onto the Ohio IT 1040 as part of your individual return. Residents with Ohio-source income must file, and non-residents must file to report income sourced to Ohio.5Ohio Department of Taxation. 2025 Ohio IT 1040 / SD 100 Instructions
What sets Ohio apart is the business income deduction. Ohio allows you to deduct up to $250,000 of qualifying business income per year ($125,000 if married filing separately). Your Schedule C net profit qualifies, so the first $250,000 is effectively shielded from Ohio’s standard rates. Business income above the $250,000 threshold is taxed at a flat 3% rather than running through the standard brackets. You calculate all of this on the Ohio Schedule of Business Income, which is part of your IT 1040.6Ohio Department of Taxation. Business Income Deduction Information
The deduction only reaches income that meets Ohio’s definition of “business income” and that was already included in your federal AGI. Rental income, for instance, may or may not qualify depending on your level of involvement in the activity. Only list amounts on the Schedule of Business Income that both appeared on your federal return and meet the state’s definition.7Ohio Legislative Service Commission. Ohio Revised Code 5747.01
Ohio requires quarterly estimated payments if you expect to owe more than $500 in state income tax for the year after credits and withholding.8Ohio Department of Taxation. Estimated Payments The 2026 due dates are April 15, June 15, September 15, and January 15, 2027.9Ohio Department of Taxation. 2026 Ohio Estimated Income Tax Payment Worksheet
Commercial Activity Tax: Probably Not You
The Commercial Activity Tax is a gross-receipts tax on the privilege of doing business in Ohio. It applies to the LLC itself rather than to you personally, and it operates independently of the LLC’s disregarded status for income tax. Most single-member LLCs owe no CAT at all.
For tax years 2025 and forward, only businesses with more than $6 million in annual Ohio taxable gross receipts must register for and pay the CAT. Below $6 million in Ohio gross receipts, you have no CAT obligation. The old $150,000 registration threshold and the $150 annual minimum tax were eliminated in earlier legislative changes.10Ohio Department of Taxation. Commercial Activity Tax
If your LLC does cross the $6 million threshold, the rate is 0.26% (2.6 mills per dollar) on taxable gross receipts above the $6 million exclusion.11Ohio Legislative Service Commission. Ohio Revised Code 5751.03 All CAT filers file quarterly, with returns due May 10, August 10, November 10, and February 10 of the following year.10Ohio Department of Taxation. Commercial Activity Tax Because the tax is on gross receipts, expenses don’t reduce the base. A high-revenue, low-margin business that clears $6 million in Ohio receipts can owe meaningful CAT relative to its actual profit. Registration goes through the Ohio Business Gateway.
Municipal Net Profit Tax
Ohio’s municipal income tax system is one of the most complex in the country. Hundreds of cities and villages tax business net profits at rates ranging from 0.5% to 3%.12Regional Income Tax Agency. Tax Rates Table As the owner of a disregarded LLC, you owe municipal net profit tax in every city where your business has nexus, and you may also owe tax to your city of residence.
Nexus generally means a physical presence or conducting business within a municipality. A home office establishes nexus in the city where the office sits. Because the LLC is disregarded, you include the LLC’s property, payroll, and gross receipts in your own municipal tax calculations.13Ohio Legislative Service Commission. Ohio Revised Code Chapter 718
Filing Through RITA or CCA
Most Ohio municipalities don’t administer their own income tax. They contract with one of two regional agencies: the Regional Income Tax Agency (RITA) or the Central Collection Agency (CCA).14Central Collection Agency. Central Collection Agency Homepage If your municipality uses RITA or CCA, you file your net profit return through that agency instead of the city directly. Operating in multiple jurisdictions served by the same agency lets you handle several returns in one portal.
When your LLC does business in more than one city, you file a net profit return in each. Apportionment formulas allocate profit across jurisdictions based on property, payroll, and sales. Your residence city generally gives you a credit for taxes paid to work cities, which prevents full double taxation, though a partial overlap is common when the work city’s rate is lower than your home city’s rate.
Estimates and Penalties
Ohio law requires quarterly municipal estimated payments if you expect to owe $200 or more in local tax for the year.15Regional Income Tax Agency. Individual FAQs – Estimated Tax Payment Requirements That threshold is lower than the state’s $500 threshold, so it’s possible to owe local estimates while owing no state estimates.
Municipal penalties are standardized under Chapter 718. A late-filed return carries a $25 monthly penalty, capped at $25 per year for tax years 2023 and beyond. Unpaid tax triggers a 15% penalty on the amount due. Interest on underpayments runs at the federal short-term rate plus 5%, which comes to 9% for 2026.16CCA – Division Of Taxation. Penalty and Interest Rates
Electing S-Corp or C-Corp Status
You aren’t stuck with disregarded entity treatment. You can elect to have the LLC taxed as an S-corporation or a C-corporation, which changes the filing picture at every level.
For S-corp status, file IRS Form 2553 no later than two months and 15 days after the beginning of the tax year the election takes effect (March 15 for calendar-year taxpayers), or any time during the preceding tax year. Miss the window and you generally wait until the following year unless you qualify for late-election relief.17Internal Revenue Service. About Form 2553, Election by a Small Business Corporation For C-corp status, file Form 8832, the entity classification election.18Internal Revenue Service. About Form 8832, Entity Classification Election Either election ends the LLC’s disregarded status, and the entity begins filing its own federal return.
The usual reason to elect S-corp status is to reduce self-employment tax. As a disregarded entity, your full Schedule C net profit takes the 15.3% hit. As an S-corp, only the salary you pay yourself is subject to employment taxes; distributions of remaining profit pass through on a Schedule K-1 and avoid self-employment tax.19Internal Revenue Service. Instructions for Schedule K-1 (Form 1120-S) The IRS requires that salary to be “reasonable” for the work you actually perform, and an S-corporation must determine and report an appropriate salary for any shareholder-employee.20Internal Revenue Service. S Corporation Employees, Shareholders and Corporate Officers The election also means running payroll, filing quarterly employment tax returns, and issuing yourself a W-2, so the compliance costs need to be weighed against the savings.
On the state side, S-corp pass-through income still lands on your Ohio IT 1040 through the K-1, and it still qualifies for the business income deduction. An S-corp election also opens the door to Ohio’s elective pass-through entity tax, which lets the entity pay a 3% tax on behalf of its owners and can create a federal deduction that works around the $10,000 SALT cap. A disregarded entity cannot make this election.21Ohio Department of Taxation. IT 4738 Electing Pass-Through Entity Income Tax Return