504 S William St, Mount Prospect, IL 60056 Property Records

Cook County property record for 504 S William St, Mount Prospect, IL 60056

Property Summary

Property Type	Single Family Home
Details	3 bd · 1.5 ba · 1,178 sqft · built 1959
Lot Size	0.194 acres (8,448 sqft)
Owner	Individual Name on Record
Last Sale	$343,000 (Jan 2018)
Tax Bill	$7,712 (2023)
Deeds & Mortgages	Jan 2018 Sale & Mortgage Nov 2017 Transfer + 1 more
Flood Zone	Zone X (minimal risk)
APN	`08-12-421-012`

Property Details

APN / Parcel Number

Primary APN	`08-12-421-012`
Alternative APN	`08-12-421-012-0000`

Interior

Bedrooms	3 Beds
Full Baths	1.5 Baths
Half Baths	1 Half Bath
Total Rooms	5 Rooms
Stories	1 Story
Building Area	1,178 sqft Living Area
1st Floor Area	1,178 sqft

Exterior

Year Built	Built 1959
Effective Year Built	Effective 1959
Architectural Style	Bungalow
Exterior Material	Brick/Stone
Construction Type	Masonry / Concrete Block
Roof Material	Asphalt
Lot Area	8,448 sqft (0.194 acres)
Garage Type	Attached
Parking Spaces	1 Parking Space

Utilities, Heating & Cooling

Cooling System	Central
Heating System	HVAC

Location & Zoning

Street Address	504 S WILLIAM ST
City	MOUNT PROSPECT
State	IL
Zip	60056-3955
Property Category	Residential
Property Type	Residential > Single Family > Home
Legal Description	LOT 69 IN ELLENDALE EAST S 30 ACRES W 40 ACRES SE4 OF SEC12 T41N R11E 3P
Legal Range	11E
Legal Township	41N
Legal Section	12
Legal Subdivision	ELLENDALE EAST
Legal Lot Number	69
Jurisdiction	COOK IL
Township / Civil Division	ELK GROVE
Census Block Group	3
Census Block	3012
Census Tract	804901

Owner

Source: Cook County records, as of May 27, 2026

Owner names and exact recorded amounts shown locked on this page are available instantly with a free trial.

Owner of Record	Individual Name on Record
Mailing Address	504 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Occupancy	Owner Occupied
Owner Type	Individual

Deeds, Mortgages & Sale History

Date	Document
Jan 16, 2018	Warranty Deed, Transfer · Conventional Mortgage GUARANTEED RATE AFFINITY LLC
Nov 27, 2017	Quit Claim Deed, Transfer Quitclaim
Sep 26, 2017	Trustee's Deed, Foreclosure Foreclosure Auction

Assessor's Deed Record

Deed Names	Name on Deed
Last Sale	Jan 16, 2018 · Amount on Record
Deed Sale	Jan 16, 2018 · Amount on Record
Prior Sale	Sep 26, 2017 · Amount on Record
Deed Document Number	201849172
Prior Transfer Date	Nov 27, 2017
Prior Transfer Doc	0000049229
Record Updated	Oct 29, 2026

January 2018: Warranty Deed, Transfer

Document Type	Warranty Deed
Jurisdiction	COOK IL
Recording Date	Jan 16, 2018
Property Address	504 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Document Number	1801649172
Instrument Date	Dec 28, 2017
Instrument	1649172
Transaction Type	Transfer
Record Updated	Jan 24, 2018
Title Company	OTHER

Transaction

Amount	Amount Recorded
Downpayment	Downpayment on Record
Loan-to-Value (LTV)	LTV on Record
Tax	$343.00
Additional	Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	5011 N WOLCOTT AVE #2N CHICAGO IL 606402659, 2N, CHICAGO, IL 60640-2659

Mortgage

Document Number	1801649173
Date	Jan 16, 2018
Instrument	1649173

Lender

Name	GUARANTEED RATE AFFINITY LLC
Address	1800 W LARCHMONT AVE, CHICAGO, IL 60613-2448

Agreement

Type	Conventional Mortgage
Amount	Amount Recorded
Term	360 Months
Due	Jan 15, 2048

Interest

Rate Type	Fixed Rate
Rate	3.87%

November 2017: Quit Claim Deed, Transfer

Document Type	Quit Claim Deed
Jurisdiction	COOK IL
Recording Date	Nov 27, 2017
Property Address	504 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Document Number	1733149229
Instrument Date	Nov 27, 2017
Instrument	33149229
Transaction Type	Transfer
Record Updated	Dec 5, 2017

Transaction

Tax	$0.00
Additional	Quitclaim

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Relationship	Company
Address	608 N DUNTON AVE ARLINGTON HEIGHTS IL 600045532, ARLINGTON HEIGHTS, IL 60004-5532

September 2017: Trustee's Deed, Foreclosure

Document Type	Trustee's Deed
Jurisdiction	COOK IL
Recording Date	Sep 26, 2017
Property Address	504 S WILLIAM ST, MOUNT PROSPECT, IL 60056-3955
Document Number	1726949065
Instrument Date	Apr 25, 2017
Instrument	26949065
Transaction Type	Foreclosure
Record Updated	Oct 10, 2017

Transaction

Amount	Amount Recorded
Tax	$218.00
Additional	Foreclosure Auction Notice of Foreclosure Sale Arm's Length

Transferred From (Grantor/Seller)

Name	Verified Name

Transferred To (Grantee/Buyer)

Name	Verified Name
Address	504 S WILLIAM ST MOUNT PROSPECT IL 600563955, MOUNT PROSPECT, IL 60056-3955

Tax Assessment & Valuation

Source: Cook County assessment roll, as of May 27, 2026

Property Jurisdictions

Type	Name
State	Illinois
County	Cook County
County Subdivision	Elk Grove Township
Municipality	Mount Prospect Village
Secondary School District	Township High School District 214 (09 - 12)
Elementary School District	Mount Prospect School District 57 (PK - 08)

Tax Bill & Assessment History

Year	Tax Bill	Assessed Value	Assessed Market Value
2025		$37,000 (+19.35%) Land $10,138 Building $26,862	$370,000 (+19.35%) Land $101,380 Building $268,620
2023	$7,712.00 (+4.41%)
2022	$7,386.00	$31,000 Land $8,448 Building $22,552	$310,000 Land $84,480 Building $225,520

Assessed value and assessed market value are set for property tax purposes, not market price estimates; both are a fraction of this property's market value.

Flood

Source: FEMA National Flood Hazard Layer, effective February 11, 2026 · OpenFEMA NFIP redacted claims and policies, as of September 2026

FEMA Flood Zone	Zone X minimal risk
Flood Insurance Requirement	Not required lenders may require it
Community Rating System	Class 6 (20% premium discount)
Nearby Flood Policies	2 in force
Nearby Flood Claims	6 (1987–2007)
Claims Outside the SFHA	2 of 6
Most Recent Claim	Aug 2007 · Severe Storms And Flooding
Claims by Event	Severe Storms & Flooding, Aug 1987 · 3 claims

Values are read at the parcel center point; flood claims are located to the census block group, not this parcel; lenders make the official flood determination.

Wildfire

Source: USDA Forest Service Wildfire Risk to Communities (2nd edition), as of 2024

Wildfire Risk	Not rated no burnable land within ember reach

Values cover an area roughly 900 ft across, not the parcel itself; insurers use their own ratings.

Drinking Water

Source: EPA Safe Drinking Water Information System, as of September 2026

Water System	MOUNT PROSPECT serves 41,000 people · EPA ID IL0311980
Water Source	Purchased surface water from NORTHWEST SUBURBAN MUNICIPAL JAWA
Last State Inspection	Aug 2025
Lead	2 ppb (2026–2028) action level 15 ppb

Violations Reported to EPA

Water Quality	None last 10 years
Treatment and Procedure	None last 10 years
Monitoring and Reporting	11 last 3 years

Results are for the whole water system, not water tested at this address; lead at the tap also depends on the building's own pipes. The service area is an EPA estimate; the actual supplier may differ.

Internet Providers

Source: FCC Broadband Data Collection, based on 671 locations within half a mile, as of December 31, 2025

Provider	Max Down / Up (Mbps)
AT&T Fiber · DSL in parts of the area	5,000 / 5,000
Xfinity Cable	2,000 / 250
Astound Broadband Cable	1,500 / 50
Verizon Fixed Wireless	1,000 / 75

May also be available: T-Mobile.

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