Tax Services in Illinois for Small Businesses
Illinois runs a flat personal income tax, but businesses face more layers underneath it. C corporations pay the state's corporate tax plus a personal property replacement tax that stacks on top of it.
Illinois has a state base rate, but many municipalities are "home rule," meaning they can layer on their own additional rate on top, so the combined rate can look very different two towns apart. Profitjets prepares your corporate or pass-through return with the replacement tax and PTE election handled correctly, registers and files your sales tax at the right combined rate for each home-rule jurisdiction you sell in, and tracks every deadline year-round.
What Our Tax Services in Illinois Cover
We build your tax strategy around your entity type and where you sell. From the corporate income tax and its personal property replacement add-on to PTE elections and home-rule sales tax, our team prepares the required state and federal forms and tracks every deadline.
Personal & pass-through tax
Illinois personal income tax (a flat 4.95%) on owner and pass-through income, prepared and filed.
Corporate income tax
Illinois's 9.5% (incl. replacement tax) corporate income tax, prepared and filed on time.
Sales & use tax
Registration, collection, and filing at Illinois's 6.25% base (up to ~11% with local) rate, with local rates applied.
Deadlines & estimates
Quarterly estimates, extensions, and notices handled year-round.
Multi-state & nexus
Operating beyond Illinois? We handle economic nexus and multi-state filings too.
Tax planning
Proactive planning to legally lower your Illinois tax bill before year-end.
Home-Rule Sales Tax, Applied Correctly
Illinois's home-rule municipalities can each add their own rate on top of the state base, so the combined rate depends heavily on exactly where a sale happens, not just which county you're in.
We register you, apply the correct combined rate for every home-rule jurisdiction you sell into, track taxable versus exempt sales, and file on schedule.
Book a Free Consultation- Registration handled
- Home-rule rates applied correctly
- Taxable vs exempt tracked
- Economic nexus monitored
- Returns filed on schedule
- Marketplace rules handled
Illinois Corporate Tax Filing & PTE Tax Planning
Your Illinois filing requirements depend on how your business is structured. C corporations owe both Corporate Income Tax and the Replacement Tax, while partnerships and S corporations may reduce owner-level tax through the Illinois PTE Tax election when it makes financial sense.
Our team prepares your Illinois corporate tax return, evaluates the right filing approach for your entity, and coordinates every federal and state filing from the same set of financial records.
Book a Free Consultation- Corporate Income Tax filing
- Replacement Tax calculation
- Pass-Through Entity (PTE) election review
- Federal & state tax preparation
- Estimated tax payments
- Multi-state filing support
How Our Illinois Tax Service Works
Discovery Call
We learn your entity type, activity, and prior filings, including whether a PTE election is already in place or worth considering.
Books & Docs Review
We review your bookkeeping and past returns and flag any replacement tax or home-rule sales tax gaps before they become a notice.
Tax Planning
We plan around your actual entity structure, weighing the PTE election and any credits your business qualifies for.
Prepare & File
We prepare and file your corporate or pass-through return, replacement tax, and sales tax returns, checked against your actual jurisdictions.
Year-Round Support
Estimates, notices, and deadlines are tracked all year, including any home-rule rate changes in the towns you sell into.
Serving businesses across Illinois
We work remotely with Illinois businesses, so you get the same dedicated team wherever you are.
What Illinois Businesses Say
The Replacement Tax We Didn't Know Existed
"We filed our corporate return for two years without realizing Illinois adds a separate replacement tax on top of the regular corporate rate. Profitjets caught it during a review, got us current, and now it's just part of the annual filing."
Home-Rule Rates Finally Consistent Across Towns
"We sell into a few different home-rule towns and our old process used one flat sales tax rate everywhere. Profitjets got each jurisdiction registered at its actual combined rate, and it's been accurate every quarter since."
PTE Election Made the Math Make Sense
"As an S-corp, we had no idea the PTE election could change how much our owners paid personally. Profitjets walked us through it, made the election, and it's saved us real money since."
Illinois tax questions
Most Illinois businesses owe the state's flat personal income tax on pass-through income, corporate income tax plus the replacement tax for C corps, and sales tax on taxable goods or services. We identify which apply to your entity type and file each on schedule.
It's a separate tax on top of the regular corporate income tax, unique to Illinois, that catches many out-of-state owners by surprise. We calculate it alongside your corporate return so nothing gets missed.
Illinois has a state base rate, but home-rule municipalities can add their own rate on top, so the combined rate varies by exactly where you sell. We register you and apply the correct combined rate for every jurisdiction.
It depends on your entity type and how income flows to owners; for many S-corps and partnerships it reduces the effective tax burden. We evaluate your specific situation and make the election if it benefits you.
If you have economic nexus in other states, you likely owe filings there as well. We monitor your nexus footprint and handle the multi-state returns.
Related services and locations
We work with businesses in Jersey City, Lafayette and Las Vegas.
Get Illinois Tax Filed Right, and Optimized
Book a free consultation and we'll map out exactly how we'd handle your Illinois business taxes.