Do Filters Have an Expiration Date?
Furnace filters do not have an “expiration date” while they are not in use; they may sit for as long as you like at your home. However, once they are in use, they do have an “expiration date” in your furnace. The manufacturer usually gives a recommended replacement schedule depending on the type of filter that you choose. Some filters need to be replaced about once a month while other air filters do not need to be replaced until 6 months or even up to a full year.