Reviewed and updated October 9, 2026 by the SearchSystems.net editorial team. Every office link was opened and checked against the office's own site between September 23, 2026 and October 4, 2026.
Mountainside, New Jersey, in Union County, has about 7,200 residents (2024 Census Bureau estimate). The title to a parcel in Mountainside is in the deed records of the County Clerk and its taxable value is set by the town assessor; what is built on it is a matter for the city. This guide says who keeps each record and where the page for each office is.
This guide covers deeds, assessed values, city permits and records, evictions and court cases, records requests and common questions.
Related guides: Mountainside public records, Union County property records, Mountainside arrest records, Mountainside warrants, Mountainside inmate search, Mountainside criminal records, New Jersey arrest records and New Jersey inmate search.
Deeds, Mortgages and Liens in Mountainside
Who owns a parcel in Mountainside and what it sold for are in the deed records of the County Clerk, with every lien or mortgage against the land.
SearchSystems opened and checked the County Clerk's page at clerk.ucnj.org/UCPA/DocIndex?s=name (page title: Union County Clerk's Office Public Land Records), which answered when SearchSystems opened it on September 23, 2026.
Assessed Values and the Tax Roll in Mountainside
The value each parcel in Mountainside is taxed on is set locally, by the tax assessor of each municipality, not by the county. New Jersey property is assessed by each municipality; the county tax board hears appeals and equalizes the values.
The county property tax office's page SearchSystems verified is at unionil.devnetwedge.com (page title: Union County Property Tax Inquiry), which answered when SearchSystems opened it on September 23, 2026.
Permits and City Records in Mountainside
Building permits, zoning and code cases are the city's own. For Mountainside, SearchSystems opened and checked the city hall page at mountainside-nj.com/department (page title: Department | Borough of Mountainside), phone 908 232 2400, 1385 US Highway 22 East Mountainside, NJ 07092, which answered when SearchSystems opened it on September 26, 2026.
Evictions and Court Cases About Land in Mountainside
Court cases about land from Mountainside, evictions among them, are filed in the Superior Court of New Jersey, Union County.
The court records page SearchSystems verified for the county is at njcourts.gov/public/find-a-case.
Asking a County Office for a Record
Under the Open Public Records Act a county office must answer a request within 7 business days, and it may charge copying at 5 cents a page for letter size.
Frequently Asked Questions
Who records deeds in Mountainside?
The County Clerk, at clerk.ucnj.org/UCPA/DocIndex?s=name. Deeds, mortgages and liens on land in Mountainside are filed there.
Who sets the assessed value of a property in Mountainside?
The tax assessor of each municipality.
Where are evictions from Mountainside filed?
In the Superior Court of New Jersey, Union County. The file is public unless the court seals it.
How is property assessed in New Jersey?
New Jersey property is assessed by each municipality; the county tax board hears appeals and equalizes the values.
Is this the official Mountainside website?
No. SearchSystems.net is an independent public records guide, online since 1997. It links to the official city, county, court and state offices described above and does not hold records, charge for them or take requests.