The Ozaukee County sales tax rate is 5.6% on most taxable purchases. That figure is the sum of three separate taxes applied to the same transaction: Wisconsin’s 5% state sales tax, Ozaukee County’s own 0.5% sales and use tax, and a 0.1% baseball stadium district tax that applies because Ozaukee is one of five counties in the stadium district, alongside Milwaukee, Racine, Washington, and Waukesha.1Department of Revenue. DOR Tax Rates2Wisconsin State Legislature. Wisconsin Code 77.70 – Adoption by County Ordinance3Wisconsin State Legislature. Stadium Sales and Use Tax Common Questions The county’s 0.5% share goes directly toward reducing the property tax levy.
What You Pay 5.6% On
The combined rate applies to retail sales, leases, licenses, and taxable services delivered in Ozaukee County. Wisconsin Statute 77.54 carves out a long list of exemptions that work at all three tax layers simultaneously.
Most food and food ingredients are exempt, but the exceptions catch people. Candy, soft drinks, dietary supplements, and prepared food are taxable.4Wisconsin State Legislature. Wisconsin Code 77.54(20n) A raw chicken from the meat case is exempt; a rotisserie chicken from the deli counter is not. Bakery items off a shelf are generally exempt, but anything heated or sold with utensils is taxable. The useful rule of thumb: if the item is ready to eat without further preparation, it’s probably taxable.
Prescription medications are exempt under section 77.54(14), along with certain medical devices such as prosthetics and blood sugar testing equipment. Over-the-counter medicines and dietary supplements are not exempt.
Tangible property used exclusively and directly in manufacturing a product for sale is also exempt, including components of the finished product and materials consumed in the process.5Wisconsin State Legislature. Wisconsin Code 77.54 – General Exemptions Equipment used partly for manufacturing and partly for other work won’t qualify.
Federal agencies, Wisconsin state and local government units, federally recognized tribal nations, and 501(c)(3) organizations can buy tax-free using a Wisconsin Sales and Use Tax Exemption Certificate (Form S-211). If the certificate is incomplete, the seller must charge tax.6Department of Revenue. Wisconsin Sales and Use Tax Exemption Certificate
Use Tax on What You Bring Into the County
A 5.6% use tax applies when you buy a taxable item outside Ozaukee County and bring it here for use, but the seller didn’t collect the full local rate. The usual trigger is an online purchase from a retailer with no Wisconsin tax obligation, though most major sellers now collect Wisconsin tax automatically. If you paid some sales tax to another state, you get credit for that amount and owe only the difference. Individuals report use tax on their Wisconsin income tax return; businesses report it through their regular sales tax filings.
How the Rate Follows the Delivery Address
Whether the 5.6% rate applies to a sale depends on sourcing rules in Wisconsin Statute 77.522, not on where the seller sits.7Wisconsin State Legislature. Wisconsin Code 77.522 – Sourcing For tangible goods, the tax rate at the delivery address controls. Buy a TV at a store in Mequon and carry it out, you pay 5.6%. Have the same TV shipped from an out-of-state warehouse to your home in Cedarburg, the Ozaukee rate still applies because the delivery destination is what matters.
Digital goods and services generally follow the same destination logic. A software subscription used at your Ozaukee County address triggers the local rate even if the seller is based elsewhere.
Remote Sellers and Online Marketplaces
Out-of-state sellers without a physical presence in Wisconsin must collect and remit Wisconsin sales tax, including Ozaukee County’s local portion, once their gross sales into the state exceed $100,000 in the current or previous calendar year. That threshold covers all sales into Wisconsin, taxable or not.8Department of Revenue. Remote Sellers – Wayfair Decision Wisconsin dropped its separate 200-transaction test in 2021, so the dollar figure is the only trigger now. Registered remote sellers must collect the county and stadium portions based on the shipping address.9Department of Revenue. Remote Sellers Common Questions
If you sell through a platform like Amazon or Etsy, Wisconsin Statute 77.523 puts the collection burden on the platform. The marketplace provider collects and remits tax on sales it facilitates, and only the provider can be audited for those transactions. Individual sellers using the platform generally are not liable, though a seller who feeds the platform incorrect product categories or tax status can lose that protection.10Wisconsin State Legislature. Wisconsin Code 77.523 – Liability of Marketplace Providers, Retailers, and Marketplace Sellers
Registering and Filing as a Seller
Any retailer making taxable sales in Wisconsin needs a Seller’s Permit before collecting tax. The registration fee is $20 regardless of how many locations you run.11Department of Revenue. DOR Business Tax Registration You can register online at tap.revenue.wi.gov/btr or file Form BTR-101 by mail.12Wisconsin State Legislature. Wisconsin Administrative Code Tax 11.002 – Registration The permit covers state and local collection together; there is no separate county permit. The Department of Revenue assigns your filing frequency (monthly, quarterly, or annually) based on expected tax liability.
All sales and use tax returns must be filed electronically through the Department’s free My Tax Account portal, which handles filing, payments, and refund claims.13Department of Revenue. DOR Sales and Use Tax Electronic Filing Options You report gross receipts and break out the amounts sourced to each local jurisdiction, and the system calculates the state, county, and stadium portions.
Penalties If You File Late or Wrong
Wisconsin’s penalty structure escalates quickly and the state isn’t particularly flexible about it.14Wisconsin State Legislature. Wisconsin Code 77.60 – Interest and Penalties
- Late filing: 5% of unpaid tax per month or partial month, capped at 25%.
- Interest on unpaid tax: 12% per year from the original due date until payment.
- Delinquent tax: interest jumps to 1.5% per month once tax becomes delinquent.
- Incorrect returns: 25% penalty if the department demonstrates the return was wrong.
- Fraud or intentional evasion: 50% penalty on top of the tax owed, plus interest.
- Improper use of exemption certificates: $250 per invoice tied to the misuse.
These penalties stack. A business that files late, underpays, and triggers a fraud finding can face the late-filing penalty, the 50% fraud penalty, and 1.5% monthly delinquent interest all running at once.
Exemption Certificates: Where Sellers Get Caught
If you accept exemption certificates, your paperwork is what stands between you and personal liability for tax the buyer should have owed. A seller who gets a properly completed certificate from the buyer before the sale, or within 90 days after, is relieved of liability on that transaction. Without the certificate, you can still protect yourself by capturing the buyer’s name, address, tax ID, business type, and exemption reason in your accounting records within the same 90-day window. Miss both, and you have one last chance: 120 days after the department asks for substantiation to produce a completed certificate or other proof the sale was exempt.15Wisconsin State Legislature. Wisconsin Administrative Code Tax 11.14 – Exemption Certificates Miss all three, and you owe the tax yourself even though the buyer was legitimately exempt.
Wisconsin can assess additional tax within four years of the return’s due date or filing date, whichever is later, so keep sales tax records at least that long.2Wisconsin State Legislature. Wisconsin Code 77.70 – Adoption by County Ordinance The limitations period can extend if the department believes you significantly underreported, and fraud allegations have no time limit at all.