Always check the regulations for the area in which you’ll be fishing. Most states require you to buy some sort of fishing license for freshwater fishing. There is now a federal license requirement in the U.S. for saltwater fishing, too (on the plus side, it costs much less than a freshwater license). If you plan to fish in a state for just a few days, you might need to purchase a license for those days. There are also license requirements for catching specific species of fish in certain areas. You can find these regulations online or contact the state’s parks and recreation department for details. Sporting goods stores that sell fishing gear may also sell licenses.