That’s because only a Carrier Factory-Authorized Dealer can sell filters for Carrier systems. Here’s the reason for that: Carrier’s furnace filters are made with higher-quality materials than the normal ones at the store. The ones at your home improvement shop are probably disposable, while most of the Carrier filters we sell are reusable—you can hand wash them in cold water and they’ll be as good as new! That means that, while they’ll cost more, you’ll get more years of use out of them.