Sources of free pallets include small businesses, distribution centers, construction sites and pallet recyclers. Online sources for finding pallets include classified sites such as Craigslist or local groups such as Facebook swap groups and local Freecycle pages.
Driving around the community is one way to spot businesses with used pallets they no longer want. Small businesses in particular tend to dispose of their own pallets, which may be near the dumpsters, loading docks or back sides of the buildings. Types of businesses that typically use pallets include stores, small manufacturers or printing companies. Larger corporations or major manufacturers likely use a service to dispose of pallets.
It's important to ask the business before just taking pallets left outside the building to avoid theft charges. This also establishes a relationship with the company. In the future, they might hold their pallets if they know someone plans to pick them up at regular intervals.
Distribution centers use a large number of pallets when shipping goods to stores. While the pallets are often reused, they may have some that no longer meet their standards. Even though the distribution center can't use them, the wood is still good enough for projects.
Some urban areas have pallet recycling companies that refurbish or recycle old pallets. The pallets that aren't good enough to fix often get dismantled. The recycling company may offer those pallets for free or for a small fee.