Chicago's Sales Tax Just Hit 10.5% - Second Highest in the Nation. Here's What Every Business Selling Into the Area Must Know.

As of August 1, Chicago has the second highest combined sales tax rate in the United States.

Chicago's combined sales tax reached 10.5% on August 1, 2026, as the Northern Illinois Transit Authority sales tax added an additional 0.25 percentage point to sales taxes across Cook, DuPage, Lake, Will, Kane, and McHenry counties. According to the Illinois Policy Institute, this brings Chicago's sales tax to the second-highest in the nation, following only Seattle. Porte Brown

But here's what most businesses don't realize: this isn't just a Chicago story.

The increase affects all of Chicago and five surrounding collar counties: DuPage, Kane, Lake, McHenry, and Will. That's a six-county region of nearly 8 million people — one of the largest metro areas in the country. Every retailer and ecommerce seller with customers anywhere in that footprint needs to have updated their systems two weeks ago. WGN Radio

If you haven't done it yet, this is your article.

What Actually Changed — The Full Story

The rate increase didn't come out of nowhere. It's the result of legislation that has been in the pipeline since late 2025.

Transit funding legislation signed by Governor JB Pritzker last December provided for the 0.25% increase to take effect on August 1 in Cook, DuPage, Kane, Lake, McHenry, and Will counties. The tax hike is projected to generate $478 million a year as part of the $1.5 billion in annual transit funding provided in Senate Bill 2111. Central Illinois Proud

The agency collecting the tax has a new name too. NITA — the Northern Illinois Transit Authority — was created by the Illinois General Assembly to replace the Regional Transportation Authority (RTA). The General Assembly passed PA 104-0457 during the 2025 Fall Veto Session. It was signed into law by Governor JB Pritzker on December 16, 2025. FOX 2

The revenue goes directly to the three major transit agencies serving the Chicago metro area — the Chicago Transit Authority (CTA), Metra commuter rail, and Pace suburban bus.

The Rates Are Different Depending on Where You Sell

This is the detail that's catching the most businesses off guard — and it's the most important compliance distinction in this entire change.

The new NITA occupation and use tax rate is 1.25% for general merchandise in Cook County and 1.50% for qualifying groceries, drugs, and medical appliances in Cook County. For businesses making sales from DuPage, Kane, Lake, McHenry, or Will County locations, the new NITA rate is 1.00% for general merchandise, qualifying groceries, and qualifying drugs and medical appliances. NFIB

In plain terms: Cook County and the five collar counties have different NITA rates. A business that sells from a Cook County location pays more than one selling from a DuPage or Will County location — even though both locations are in the NITA coverage area.

For businesses making sales from a Cook County location, the new NITA occupation and use tax rate is 1.25% for general merchandise and 1.50% for qualifying groceries, drugs, and medical appliances. For businesses making sales from DuPage, Kane, Lake, McHenry, or Will County locations, the new NITA rate is 1.00% for general merchandise, qualifying groceries, and qualifying drugs and medical appliances. The Black Chronicle

This rate difference matters enormously for ecommerce sellers using origin-based tax calculation — and for retailers with locations in multiple counties within the NITA footprint.

What the Combined Rates Look Like Now

Chicago's 10.5% combined rate is the most visible — and the most talked about. But the rate picture across the six-county NITA area is more nuanced.

Chicago sits at 10.5% because it layers the Illinois state rate, Cook County tax, Chicago home rule tax, and now the new 1.25% NITA rate on top of each other. That 10.5% applies to general merchandise purchases in the city proper.

In the collar counties, the combined rate is lower — but still meaningfully higher than it was on July 31. Naperville in DuPage County, Aurora in Kane County, Waukegan in Lake County, and Joliet in Will County all saw their combined rates increase by 0.25 percentage points on August 1.

According to the Daily Herald, the increase means consumers are paying $2.50 more on every $1,000 spent in the region on purchases as of August 1. CJBS Accounting Firm

For businesses, the compliance obligation tracks the delivery address — not the business's location. An ecommerce seller based in California shipping to a Naperville customer owes the Naperville combined rate, which now includes the new NITA component.

The Grocery and Drug Rate — A Separate Calculation

Illinois taxes groceries and drugs at a different rate than general merchandise — and the NITA increase applies differently to these categories too.

In Cook County, the NITA rate on qualifying groceries and qualifying drugs is 1.50% — higher than the 1.25% on general merchandise. In the five collar counties, the NITA rate on qualifying groceries and drugs is the same 1.00% as general merchandise.

For retailers selling food or pharmaceutical products in Cook County specifically, the blended rate on grocery transactions is now higher than it was on July 31 — and the increase is larger than the general merchandise bump.

This applies to many common types of sales, including general merchandise, qualifying groceries, qualifying drugs and medical appliances, titled or registered items, cannabis, and aviation fuel. Weiss CPA

Cannabis retailers in Cook County — already navigating one of the most complex tax environments in the country — have another rate component to incorporate into their calculations.

The Political Reaction — Collar Counties Are Not Happy

The transit funding rationale for the increase is straightforward: Chicago's CTA, Metra, and Pace all need capital investment and operating funding. Senate Bill 2111 provided that funding. The 0.25% sales tax across six counties was the revenue mechanism.

But the political reaction from suburban legislators has been sharp — particularly from representatives whose constituents use the transit system rarely or not at all.

State Rep. Steven Reick, R-Woodstock, said suburban taxpayers are bailing out the Chicago Transit Authority. "We're giving them a lifeline of money that we're not getting anything in return for," Reick said. Central Illinois Proud

In McHenry County, Reick said most regularly-scheduled Pace buses run empty. "If we could work out an intergovernmental agreement with Metra to keep rail service coming out here to McHenry County, I wouldn't have a problem if our county board put a referendum on the ballot to get us out of this thing completely," Reick said.

The border shopping effect is already being discussed. Reick noted that McHenry County is on the border with Wisconsin, suggesting people might make economic choices to drive up to Walworth, Wisconsin to buy gas and other items. Eccezion

This is the same dynamic we've covered all year — from Massachusetts residents crossing into New Hampshire to Indiana's gas tax suspension driving border decisions. When a combined rate hits 10.5%, the calculation for major purchases changes.

What Small Businesses Are Saying

Sara Plocker, owner of local boutique Sara Jane, said: "All we ever do is just keep raising the prices and raising the prices and raising the prices, and doing more, not cutting back on anything, or living within the lane that you should or what we can afford." WGN Radio

The frustration reflects a broader reality for Chicago-area small retailers. Illinois already has the highest average combined sales tax rate in the Midwest at 8.98% statewide. The City of Chicago has layered multiple additional local taxes on top of that — a home rule tax, a Chicago Simplified Municipal Tax, the new NITA rate, and various transaction-specific taxes on restaurants, parking, and hotels.

For retailers already operating on thin margins in one of the country's most competitive urban markets, a 0.25% increase may seem small in isolation. In context — stacked on top of years of incremental increases — it feels like one more weight on an already strained balance sheet.

The Second-Highest-in-the-Nation Context

Chicago's 10.5% combined rate makes it the second-highest sales tax rate in the nation, following only Seattle. Porte Brown

That comparison is worth sitting with. Seattle's high combined rate — driven by Washington State's lack of an income tax and significant local additions — has been a well-documented source of consumer behavior effects, border shopping, and business location decisions for years.

Chicago's rate is now in the same territory. At 10.5%, a consumer buying a $1,000 item in Chicago pays $105 in sales tax. The same item purchased online from an out-of-state seller without nexus in Illinois — while technically subject to use tax — may escape collection entirely if that seller hasn't registered.

The enforcement pressure to close that gap is growing. Illinois's AI-powered audit selection capabilities have improved significantly in 2026. The economic incentive for out-of-state sellers to avoid Illinois registration — which always existed — is now larger than ever. Both dynamics will intensify the compliance environment for registered sellers in the months ahead.

What Ecommerce Sellers Need to Know

The NITA increase is destination-based — it applies where the customer is, not where the seller is.

Whether you operate a storefront, sell online, or deliver products into these counties, reviewing your sales tax setup now can help you avoid collecting the wrong amount of tax and reduce potential compliance issues. Ymaws

For ecommerce sellers with Illinois economic nexus — $100,000 in annual Illinois sales — the August 1 rate change means every delivery to a Cook County, DuPage County, Kane County, Lake County, McHenry County, or Will County address now carries a higher rate than it did on July 31.

If your tax software updates automatically, verify the update happened correctly. If you manage rates manually, update your rate tables for all six affected counties immediately. If you use a marketplace facilitator that collects Illinois taxes on your behalf, verify the platform updated its rates for the affected jurisdictions on August 1.

The Compliance Checklist — What To Do Right Now

Businesses should update their point-of-sale and accounting systems to make sure cash registers, point-of-sale software, accounting software, and any other systems used to calculate sales tax are updated to use the new tax rates beginning August 1, 2026. Continuing to use outdated rates could result in collecting the wrong amount of tax from customers. Illinoisstateauthority

The specific steps:

1. Identify every location and delivery address in the six-county NITA area. The affected counties are Cook, DuPage, Kane, Lake, McHenry, and Will. Any retail location or ecommerce delivery address in these counties needs the updated rate.

2. Apply the correct NITA rate for your county. Cook County businesses apply 1.25% for general merchandise and 1.50% for groceries and drugs. Collar county businesses apply 1.00% for all categories. These rates are not interchangeable.

3. Verify your software updated on August 1. If your business uses a third-party provider to calculate sales tax automatically, contact them to confirm they are aware of the changes and have updated accordingly. Don't assume — verify. Illinoisstateauthority

4. Use the MyTax Illinois Tax Rate Finder. You can look up your local tax rate using the MyTax Illinois Tax Rate Finder to confirm your updated combined sales tax rate for any specific address in the affected area. CJBS Accounting Firm

5. Review your August transactions. If you've been collecting the old rate since August 1, you've been under-collecting. Address the gap immediately — the liability sits with the retailer, not the customer, in most cases.

6. Update your Illinois NITA-period returns. When filing your August Illinois return — due September 22 because September 20 falls on a Sunday — make sure the new NITA rate is reflected in your reported collections for Cook County and collar county transactions separately.

The Broader Illinois Context

This rate change doesn't exist in isolation. August 2026 has been one of the most complex compliance months in Illinois history.

Illinois started August with the back-to-school holiday reducing the state rate on qualifying clothing and school supplies to 1.25% through August 16. Simultaneously, the NITA increase added 0.25% to six counties' base rates from August 1. And the Illinois budget passed June 1 included new taxes on social media, digital assets, fantasy sports, and crypto that are working their way through implementation.

For businesses operating in Illinois — particularly in the Chicago metro area — 2026 has required more active compliance monitoring than any recent year. The rate you were collecting in January is not the rate you should be collecting in August. And the rate you're collecting in August may not be the rate you'll collect in October when Washington D.C.'s 7% rate takes effect and other state-level changes roll through.

The compliance environment is not getting simpler. The businesses that stay ahead of it are the ones that build a process for monitoring rate changes rather than reacting to them after the fact.

Operating a business in the Chicago metro area or selling to customers in Cook County or the Illinois collar counties — and want to confirm your systems reflect the correct NITA rates for every affected jurisdiction? Book a free consultation with our team at sales.tax. We'll verify your Illinois compliance setup and make sure you're collecting the right amount before your next filing deadline.