If you receive a letter from any company offering to lower property taxes on your home, don't be fooled. While these letters appear official, they did not come from any government agency. You NEVER have to pay for a review of your property's value. The Los Angeles County Assessor's Office does this completely FREE OF CHARGE.

Decline-in-value reassessment Proposition 8 applications are easy to complete and can be downloaded from the Assessors site.
Go to: http://www.assessor.lacounty.gov or just give them a call at 1-888-807-2111.