Specialized accounting, tax planning, and Illinois sales tax compliance for Chicago online sellers, Amazon FBA businesses, and high-growth e-commerce brands. We handle Illinois’s complex multi-jurisdictional tax environment — so you can focus on scaling.
Serving Chicago e-commerce sellers & Amazon FBA businesses — Schedule your free consultation today →
The Online Seller CPA is a boutique accounting firm built exclusively for the e-commerce industry. We do not serve general business clients or traditional retail — every client we work with is an online seller, and every member of our team has deep expertise in the platforms, payment processors, marketplace economics, and tax rules that define modern e-commerce.
Chicago is one of the most active e-commerce markets in the Midwest. The greater Chicago area is home to one of Amazon’s densest fulfillment center clusters in North America, with major facilities in Joliet, Romeoville, Channahon, Aurora, Waukegan, Huntley, University Park, and Wilmington — all in Illinois. Illinois’s sales and use tax system is among the most complex in the country: it is actually composed of four distinct taxes (Retailers’ Occupation Tax, Service Occupation Tax, Service Use Tax, and Use Tax), with Chicago adding one of the highest combined local rates in the nation at 10.25%.
Whether you are a solo Amazon FBA seller building your first private label brand or a multi-channel DTC company selling across Amazon, Shopify, and Walmart, our team delivers the same standard of precise, proactive, and professional financial service.
Meet Our Team →Our full suite of accounting, tax, and advisory services is purpose-built for the demands of Chicago online sellers and Amazon FBA businesses operating in Illinois’s uniquely complex tax environment.
Year-round federal and Illinois state tax planning for Chicago online sellers. We optimize entity structure, manage quarterly estimated tax payments to both the IRS and Illinois Department of Revenue, and identify every legal deduction available — from COGS and software to home office and fulfillment costs.
Specialized bookkeeping and financial reporting for Amazon FBA and FBM sellers in Chicago. We reconcile Amazon settlement reports, track FBA fees and reimbursements, manage inventory valuation, and produce accurate P&L statements that reflect true seller economics.
Complete management of Illinois sales tax obligations across all four tax types. This includes nexus analysis, IDOR registration, return preparation and filing under Illinois’s destination-sourcing rules, economic nexus monitoring, and audit defense support.
Clean, accurate, and timely monthly bookkeeping aligned with your e-commerce platforms and payment processors. We categorize every transaction, reconcile all channels, and deliver financial statements that give you a true picture of revenue, expenses, and cash flow.
Amazon FBA sellers with inventory in Illinois fulfillment centers — or other warehouses nationwide — may have nexus obligations across multiple states. We manage registration, filing, and compliance in every required jurisdiction, including voluntary disclosure for historical exposure.
Beyond compliance, your CPA serves as a financial partner. We provide cash flow forecasting, pricing and margin analysis, inventory cost optimization, entity structuring guidance, and expansion planning — helping Chicago e-commerce sellers scale confidently.
Amazon FBA and FBM selling introduces a distinct set of financial, tax, and accounting challenges that general CPA firms are ill-equipped to handle. Settlement report reconciliation, FBA fee tracking, multi-state nexus from warehouse inventory, and COGS calculations specific to Amazon’s fulfillment model all require a genuine specialist — not an accountant trying to learn as they go.
The greater Chicago area is one of Amazon’s most important logistics hubs in North America. Fulfillment centers operating in the Chicago metro include MDW4 and MDW6 (Joliet), MDW7 (Monee), MDW8 (Waukegan), MDW9 (Aurora), ORD2 (Channahon), RFD4 (Huntley), IGQ2 (University Park), HMW1 (Wilmington), and several additional facilities in Will County — all creating physical nexus in Illinois for FBA sellers whose inventory is routed through these warehouses, regardless of where those sellers are headquartered.
The Online Seller CPA has worked with Amazon sellers at every revenue tier — from early-stage FBA sellers building their first private label product to seven-figure brand owners managing hundreds of ASINs. Our Amazon seller accounting practice is built around accurate profitability by ASIN, clean books ready for investors or lenders, and a tax strategy that keeps more of your Amazon revenue in your business.
Talk to an Amazon Seller CPA →We reconcile every bi-weekly Amazon settlement report against payouts, fees, refunds, and reimbursements — ensuring your books match your bank account to the dollar.
Accurate tracking of landed costs, inbound shipping, prep fees, storage, and fulfillment charges to calculate true Cost of Goods Sold and per-unit profitability for every ASIN.
Amazon routes inventory through multiple fulfillment centers in the Chicago metro, creating Illinois sales tax nexus for FBA sellers from any state. We track placements and manage all IDOR compliance obligations.
We systematically track FBA reimbursements for lost, damaged, or destroyed inventory to ensure you capture every dollar Amazon owes your business.
Planning to sell your Amazon business? We prepare acquisition-ready financials, calculate SDE and EBITDA, and ensure your books satisfy buyer due diligence requirements.
Chicago’s combined sales tax rate of 10.25% is one of the highest in the country. Remote sellers shipping to Chicago must apply destination-based rates correctly — a critical compliance requirement under Illinois’s Leveling the Playing Field Act.
Illinois operates one of the most structurally complex sales and use tax systems in the United States. What most people call “Illinois sales tax” is actually four separate taxes: the Retailers’ Occupation Tax, the Service Occupation Tax, the Service Use Tax, and the Use Tax. These taxes interact differently depending on whether a seller is in-state or remote, and whether they are shipping from within or outside Illinois.
Illinois’s state base sales tax rate is 6.25%, but Chicago’s combined state and local rate reaches 10.25% — one of the highest combined rates of any major city in the country. Under the Leveling the Playing Field for Illinois Retail Act (effective January 1, 2021), remote sellers must apply destination-based sourcing, collecting the full state and local rate at the buyer’s delivery address. This means a seller shipping to a Chicago address must collect 10.25%, not just the 6.25% state rate.
As of January 1, 2026, Illinois eliminated the 200-transaction threshold for economic nexus. Economic nexus is now determined solely by the $100,000 gross receipts threshold. Combined with Amazon’s massive fulfillment center presence across Will County and the broader Chicago metro, many online sellers have Illinois sales tax obligations they are unaware of. Working with a dedicated e-commerce CPA in Chicago ensures these obligations are identified and managed before they escalate into penalties or audit risk.
Illinois’s sales tax system is actually four distinct taxes. Remote sellers must navigate the Retailers’ Occupation Tax, Service Occupation Tax, Service Use Tax, and Use Tax — each with different rules, rates, and filing mechanics that a general CPA is unlikely to handle correctly.
Under Illinois’s Leveling the Playing Field Act, remote sellers must apply the full destination-based combined rate. Shipping to a Chicago address requires collecting 10.25% — not just the 6.25% state rate. Many sellers are under-collecting significantly.
Amazon operates numerous fulfillment centers in Will, DuPage, Kane, and Lake Counties in the Chicago metro. Inventory stored at MDW4, MDW6, MDW7, MDW8, MDW9, ORD2, or RFD4 creates physical nexus for FBA sellers from any state, from the first dollar of inventory.
Our onboarding process is designed to be fast, efficient, and tailored to your Chicago e-commerce business from day one.
Schedule a complimentary call with a senior CPA to discuss your business, platforms, revenue, and current financial or compliance challenges.
We assess your specific needs and present a transparent, flat-fee proposal covering accounting, tax, and any advisory services required for your business.
We connect your platforms, integrate your accounting software, and clean up any historical bookkeeping to establish a solid, accurate financial foundation.
Monthly financial reports, quarterly tax reviews, and proactive advisory throughout the year — your finances are always organized and optimized.
Real results from real online sellers who trusted us with their financial operations.
“I had no idea that Amazon routing my inventory through the Joliet and Romeoville fulfillment centers created an Illinois tax obligation — let alone that Chicago’s rate is 10.25% for destination sales. The Online Seller CPA fixed years of under-collection and got us fully compliant. Exceptional service.”
“Running both a Shopify store and Amazon FBA out of the Chicago suburbs was a compliance nightmare until we found this team. They set up A2X, cleaned our books, and helped us understand Illinois’s four-tax structure for the first time. Real margin visibility, finally.”
“We sell digital and physical products and had unrecognized Illinois sales tax exposure on both. The Online Seller CPA was the first firm to correctly map our obligations under the Leveling the Playing Field Act. They restructured our compliance approach and saved us from a significant audit risk.”
Common questions from Chicago e-commerce sellers and Amazon FBA businesses considering our CPA services.
Whether you are an Amazon seller, a Shopify brand, or a multi-channel e-commerce business in Chicago, our team is ready to help you achieve compliance, reduce your tax burden, and scale with financial confidence.
Take control of your personal finances—without the stress.
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