Illinois base state sales tax rate before local taxes.
Remote sellers should monitor Illinois retail sales against the current economic nexus threshold.
Illinois registration, filing, payments, and account management commonly flow through MyTax Illinois.
Quick answer for ecommerce sellers.
If you sell taxable products or taxable services into Illinois, you may need to register, collect, file, and remit Illinois sales tax if you have Illinois physical presence or meet Illinois economic nexus rules. In 2026, remote sellers should focus on the $100,000 Illinois retail-sales threshold rather than relying on old transaction-count language.
Illinois returns need clean supporting data: direct ecommerce sales, marketplace sales, local sourcing, exempt or resale sales, refunds, tax collected, and MyTax Illinois confirmations.
What creates Illinois sales tax nexus?
Illinois nexus can come from physical presence, inventory, employees, representatives, affiliates, or remote selling volume. Merchants should review fulfillment locations, marketplace activity, direct ecommerce sales, and local delivery locations before registration decisions.
- Physical presence: inventory, employees, warehouses, offices, contractors, or representatives in Illinois can create obligations.
- Economic nexus: monitor Illinois retail sales against the $100,000 threshold.
- Marketplace activity: marketplace sales should be separated from direct sales for nexus review and filing prep.
- Local sourcing: combined rates vary by delivery location, so address quality and rate mapping matter.
How Illinois registration fits into the workflow.
Illinois sellers commonly register and manage accounts through MyTax Illinois. Before registration, gather the entity name, EIN, responsible party, business address, sales start date, product categories, marketplace channels, payment owner, and filing owner.
After registration, save the Illinois account details, MyTax login owner, filing frequency, local-rate process, exemption handling, payment method, and reviewer assignment in the compliance workspace.
Collection, local rates, and marketplace sales.
Illinois has a 6.25% base state rate, but local taxes can raise the combined rate. Chicago, Cook County, and other local jurisdictions can make a visible difference, so ecommerce sellers should preserve delivery-location data and platform tax settings.
- Direct ecommerce sales: orders where the merchant is seller of record and may need to collect Illinois tax.
- Marketplace sales: Amazon, Walmart, Etsy, eBay, and other marketplace orders should be isolated before filing prep.
- Local rates: document delivery address, jurisdiction, tax rate, and platform calculation support.
- Exempt sales: retain resale certificates, E-numbers, and other exemption support.
- Refunds and adjustments: credits, returns, and tax adjustments should tie to the filing period.
How to prepare an Illinois sales tax filing packet.
Illinois sellers commonly file and pay through MyTax Illinois. Monthly, quarterly, and annual filing frequencies can apply, and returns are commonly due by the 20th day after the reporting period. Use the frequency assigned to the account.
- Export exact-period reports: pull order, refund, tax, marketplace, exemption, and payout reports.
- Separate channels: split direct ecommerce orders from marketplace-facilitated sales.
- Map Illinois totals: document gross receipts, taxable sales, exemptions, local taxes, deductions, and tax collected.
- Reconcile data: compare platform tax, payment processor data, accounting, and marketplace reports.
- Prepare reviewer notes: record source files, assumptions, exceptions, preparer, reviewer, and approval time.
- Save proof: keep the MyTax confirmation, payment receipt, source exports, and final workpapers together.
What happens if Illinois filings are late or unsupported?
Late filing, late payment, incorrect local-rate sourcing, unsupported exemptions, marketplace duplication, and weak records can create penalties, interest, amended returns, notices, or audit work. Illinois filings should be traceable back to source exports and platform tax calculations.
Before filing, review this checklist:
- Does the filing period match every source export?
- Are direct and marketplace sales separated?
- Does each order have enough location detail for local rate review?
- Are resale and exemption records saved?
- Do refunds and tax collected reconcile to accounting?
- Was the MyTax filing confirmation and payment proof saved?
Illinois sales tax FAQ.
What is Illinois economic nexus?
Illinois remote sellers should monitor whether Illinois retail sales exceed $100,000 during the relevant preceding 12-month review period.
Does Illinois still use a 200-transaction threshold?
As of 2026, sellers should not rely on the old 200-transaction threshold as current Illinois economic nexus guidance.
What is the Illinois sales tax rate?
Illinois has a 6.25% base state sales tax rate. Local taxes can increase the combined rate depending on the delivery location.
Where do Illinois sellers file?
Illinois sellers commonly register, file, and pay through MyTax Illinois.
Can AtomicTax help file Illinois returns?
Yes. AtomicTax helps ecommerce merchants prepare filing-ready packets and complete standard sales tax filings for $45 per filing.
Official Illinois resources to check.
Need help making Illinois filings repeatable?
AtomicTax prepares sales tax filing packets from ecommerce reports, separates marketplace and direct-channel activity, and helps merchants keep every filing period reviewable.