Discovering that your home is being taxed at a higher value than it is worth means it’s time to start grieving. But don’t worry—that doesn’t mean investing in a box of tissues and complaining. Filing a grievance against the town’s valuation of a home can reduce its taxes for the following three years.

To begin the process, a homeowner needs to establish that the home has been appraised at a higher price than current market value. This can be done by proving that comparable homes in the neighborhood sold within the last year for less than your home’s value (as indicated on the tax bill). Attorney Dale Allinson, real estate tax partner at Certilman Balin Adler & Hyman, said a key for homeowners to remember is that both Nassau and Suffolk counties have specific grievance deadlines; March 1 for Nassau and May 20 for Suffolk.

Successfully grieving taxes can take anywhere from a year to two years. Suffolk County homeowners grieve for the current year’s taxes and can expect to wait another 12 to 15 months to receive their refunds. Nassau homeowners file for the next year’s taxes and usually do not receive refunds because the county generally tries to resolve the case and adjust the bill before it comes out. Before filing, homeowners should gather the necessary paperwork; forms can be found on each county’s website. “You need proof of the recent market value of your home,” Allinson said. “You can research comparable sales in your neighborhood, but the best evidence is if you have recently purchased your home [fusion_builder_container hundred_percent=”yes” overflow=”visible”][fusion_builder_row][fusion_builder_column type=”1_1″ background_position=”left top” background_color=”” border_size=”” border_color=”” border_style=”solid” spacing=”yes” background_image=”” background_repeat=”no-repeat” padding=”” margin_top=”0px” margin_bottom=”0px” class=”” id=”” animation_type=”” animation_speed=”0.3″ animation_direction=”left” hide_on_mobile=”no” center_content=”no” min_height=”none”][for a certain value].” Residents must initially complete the pages of NYS Form RP-525 and submit it to the county’s assessor’s office. If denied, the RPTL-730 can be submitted to the county clerk’s office.

If the thought of all that paperwork and court time is overwhelming, homeowners can leave the filing in the hands of a specialized property tax grievance firm. According to Adam Heller, founder and CEO of Heller & Consultants Tax Grievance , this can save the homeowner headaches as these services usually take care of everything. “In Suffolk County, the overwhelming majority of cases are declined at the Board of Assessment Review. This requires taking the town to Small Claims Assessment Review, a division of the New York State Supreme Court,” Heller said. “Unless the consumer is familiar with the NYS Supreme Court system and has access to an appraisal completed by a licensed appraiser, they will likely be better suited to have a property tax grievance company handle the process.”

Heller said last year he saved a client in Nassau $21,589 a year while someone else with a similar house on the same street only trimmed $3,500 a year off the property tax. He pointed to the importance of starting the process with the right assessment. Most grievance services charge up to 50 percent of first year’s savings, plus a $75 appraisal fee and a $30 court fee.

Allinson and Heller agree that the sooner the process is started, the better. “What I hear from my clients all the time is that they wish they started the process sooner because it is so lengthy,” Heller said. “You can’t grieve past tax years, so they should begin right away.”