Affiliate disclosure: This page contains affiliate links. We may earn a commission if you use them, at no extra cost to you. Our editorial recommendations are independent of these relationships.
Illinois · Chicago Northern Suburbs · Great Lakes · #98 Most Populous County in the US
Lake County, Illinois
Chicago's northern collar county - Highland Park, Lake Forest, Waukegan, and the shores of Lake Michigan. Illinois property tax, township-based Board of Review appeals, courts, probate, and senior services for Lake County residents.
County SeatWaukegan
Population714,342
County image
Affiliate disclosure: This page contains affiliate links. We may earn a commission if you use them, at no extra cost to you. Our editorial recommendations are independent of these relationships.
What do you need to do?
Tell us your goal and we'll guide you step-by-step to the right office, forms, and official resources.
Lake County is Chicago’s northern collar county – a 1,368-square-mile county bordering Lake Michigan and Wisconsin, containing some of the wealthiest communities in Illinois alongside more working-class cities. Lake Forest and Barrington Hills are among Illinois’s most exclusive addresses; Waukegan is the county seat and a diverse industrial city; Libertyville, Highland Park, Deerfield, Vernon Hills, Gurnee, and Zion round out the county’s wide range of communities. Lake County contains the Waukegan National Airport, Great Lakes Naval Station (now Naval Station Great Lakes, the Navy’s primary enlisted training center), and Six Flags Great America.
Lake County government is led by an elected County Board Chairman and 21-member County Board, with independently elected offices for the County Clerk, State’s Attorney, Sheriff, Treasurer, Circuit Court Clerk, Coroner, Auditor, and Recorder. Property assessment in Illinois is done at the township level – each of Lake County’s townships has its own elected assessor – with oversight from the Chief County Assessment Office (CCAO) in Waukegan.
Illinois is infamous for having the second-highest property taxes in the United States, and Lake County embodies that – over 200 individual taxing entities levy against properties in the county, with school districts receiving approximately 69% of the average tax bill. The county government itself receives only about 7% of the average bill.
All Services
Browse every category and topic available for this county.
Illinois assesses property at 33.3% of fair market value (one-third). The state then applies an equalization factor (multiplier) to bring each county’s assessments into alignment statewide. The resulting Equalized Assessed Value (EAV) is what tax rates are applied to. Illinois taxes are billed in arrears – your 2025 tax year bill is paid in 2026.
Assessment in Lake County is done at the township level by elected township assessors. The Chief County Assessment Office (CCAO) at 18 N. County Street, 7th Floor, Waukegan (847-377-2050) oversees the process and provides taxpayer assistance.
The appeal process – township-based, 30-day window:
Assessment notices are published for each township separately throughout the year. Once published, property owners have 30 days to appeal. The deadline date for each property is listed on the assessment notice – there is no single countywide deadline. All appeals are filed electronically through the SmartFile E-Filing Portal at lakecountyilpaefile.tylertech.com.
Step 1: Contact your local township assessor to discuss concerns informally – many issues can be resolved here without a formal appeal.
Step 2: File electronically through SmartFile with the Lake County Board of Review. Upload your evidence – comparable sales from the county’s grid form, a recent appraisal (for ad valorem purposes, valued as of January 1), or documentation of a recent arm’s-length purchase. No attorney required for residential appeals. Corporations and LLCs must use an attorney.
Step 3: Hearings can be conducted in person, by phone, by Zoom video, or by letter – most cases are resolved without an in-person hearing when supported by a recent purchase or a licensed appraisal. The Board conducts hearings under oath.
Step 4: If unsatisfied with the Board of Review decision, appeal to the Illinois Property Tax Appeal Board (PTAB) – a quasi-judicial state body providing a new hearing. PTAB decisions can apply for up to four years until the next quadrennial reassessment.
Illinois homestead exemptions (all deadlines July 31 for next year’s bill):
– General Homestead Exemption: $6,000 EAV reduction for primary residences
– Senior Freeze (65+, income limits): freezes EAV for qualifying seniors
– Home Improvement Exemption: excludes qualifying improvements for 4 years
– Disabled Veterans and Returning Veterans exemptions also available
Apply through the CCAO at 18 N. County Street, Waukegan (847-377-2050).
Illinois has no state estate tax and no state inheritance tax.
OWNWELL CTA: Lake County’s 2.94% effective rate is among the highest in Illinois – and with over 200 taxing entities, the complexity is real. Appeal deadline is 30 days from township publication – check your assessment notice. SmartFile e-filing required. Ownwell manages the process with no upfront cost.
Recommended
Lake County's 2.94% effective rate is among the highest in Illinois - and with over 200 taxing entities, the complexity is real. Appeal deadline is 30 days from township publication - check your assessment notice. SmartFile e-filing required. Ownwell manages the process with no upfront cost.
Courts & Legal
Courts & Legal
The Lake County Circuit Court (19th Judicial Circuit) at 18 N. County Street, Waukegan (847-377-3380) handles all civil, criminal, family, and probate matters. The Lake County Recorder of Deeds at 18 N. County Street, Waukegan (847-377-2575) maintains all land records – deeds, mortgages, and recorded documents. The Lake County Clerk (847-377-2400) maintains vital records, marriage licenses, and election records.
Illinois probate is governed by the Probate Act of 1975 (755 ILCS 5). Illinois has no state estate tax and no state inheritance tax – only federal estate tax applies. Illinois recognizes joint tenancy with right of survivorship and Transfer on Death instruments (TODI) for real property.
Senior Services: The Lake County Partners for Health and the Council on Aging – Lake County (847-336-1043) coordinate senior programming, home-delivered meals, transportation, SHIP Medicare counseling, and Adult Protective Services. Illinois’s Community Care Program (CCP) provides Medicaid-funded in-home care for qualifying seniors.
Editorial independence: CountyOffices maintains strict editorial independence from our affiliate partners. Our content is researched from official government sources. Affiliate relationships do not influence our recommendations or the information we publish.
Recommended for Illinois
Ownwell
Property tax appeal service. Contingency fee - no savings, no charge.