As of March 2015, Holmes humidifier filters are available from the company's website, Best Buy and Amazon.com. Some are designated for specific humidifiers, while others fit multiple models.
On its online store, Holmes sells filters for less than their suggested retail prices. The site has filters for both small- and whole-house humidifiers. Many of the filters have user reviews.
Best Buy directly fulfills some of its filter orders, while others are completed by approved third-party retailers. Both single filters and multiple packs are offered.
Many of the Holmes filters at Amazon.com are advertised at prices less than retail cost. Discounted subscriptions are also available for automatic refill of the filter order. Reviews are available for some filters.