Fairfax County provides real estate tax relief and car tax relief to citizens who are either 65 or older, or permanently and totally disabled. Fairfax County provides real estate tax relief and vehicle ("car") tax relief to citizens who are either 65 or older, or permanently and totally disabled.The Homestead benefit is limited to residential property. Review the credits below to see what you may be able to deduct from the tax you owe. Taxpayers can complete transactions on MyTax DC or call 202-727-4TAX. You must fill-in the property identification number in order to submit this application.