40.5% of homes in Imperial County are overassessed.

Imperial County is a growing California county with an average effective property tax rate of 1.05%. Under Proposition 13, California properties are assessed at acquisition value (not annual market value). However, new construction, changes of ownership, and Prop 19 transfers re-set the base year value — and reassessment errors frequently occur at these events. But here's the problem: the Imperial County Assessor is responsible for valuing tens of thousands of properties every year using mass appraisal models that cannot account for the specific condition, improvements, or market dynamics of your individual home.

According to statewide California property tax data, roughly 40.5% of residential properties are assessed above their true fair market value — meaning homeowners are legally being charged more than they owe under California law. In Imperial County alone, that's an estimated 24,300 households paying too much right now.

At the county's 1.05% effective rate, every $10,000 of overassessment costs you $105 per year. Over a nine-year median homeownership period, that's $949 lost on just $10,000 of excess assessed value.

The Imperial County assessor is responsible for valuing every property in the county annually. Mass appraisal models make systematic errors — and California law gives you the right to correct those errors through the formal Assessment Appeals Board appeal process. The county has no incentive to notify you when you're overpaying. You have to check yourself.

California assessment appeals go to the county's Assessment Appeals Board (AAB). Most hearings are informal; the assessor and property owner both present evidence to a three-member board of trained hearing officers. To win, you need evidence. The most compelling evidence is recent comparable sales — homes similar to yours in Imperial County that sold at prices implying a lower value than your assessment. A licensed appraisal is also highly effective.

Your assessment can only go down from an appeal, never up. California law prohibits assessors from raising your value as a result of an appeal you initiate. The only risk is the time it takes to file — which is why Fairmark does it for you.

These figures represent the average overassessment in counties with Imperial County's tax profile. Your specific situation may differ — the only way to know is to check your assessed value against what your home would actually sell for today.

Fairmark Complete is $0 today — 25% of first-year savings only if we win. We file your property tax appeal, gather comparable sales evidence, and handle every step of the process remotely. You never attend a hearing or fill out a form. If the county doesn't reduce your assessment, you owe nothing.

86% of pre-screened appeals in California result in a reduction. The assessor's office knows their valuations are imperfect. When presented with credible evidence, they typically settle.

Nationwide, only about 5% of eligible homeowners appeal their property tax assessment each year — despite roughly 40% being overassessed. The gap exists for three reasons:

First, 53% of homeowners don't know they can appeal. The annual tax notice contains a legal disclosure of your appeal rights — but it's buried in fine print that most people skip. The county is legally required to disclose your appeal rights, but not to make them easy to act on.

Second, gathering evidence feels overwhelming. Pulling comparable sales data, analyzing assessment methodology, and building a credible case against the county's own records takes time and expertise most homeowners don't have.

Third, the county has no incentive to help you. Every dollar of overassessment is revenue. The system is designed to be just difficult enough that most people give up. We don't. Enter your address above and we'll show you exactly what you're overpaying — for free.