Trout stamp

States that stock trout generally pay for the hatcheries and the stocking trucks with a dedicated fee rather than out of the general licence. The result is that a standard freshwater licence covers bass, panfish and catfish but does not, on its own, entitle you to fish for trout. The name varies by state: trout stamp, trout permit, trout validation.

It is bought the same way as the licence itself, online in a couple of minutes, and it is the single most commonly missed requirement by people trying trout fishing for the first time. Buying it the night before rather than discovering it at the water costs nothing and avoids a citation.

Trout waters also carry more special regulations than nearly any other freshwater fishing. Opening dates, closed pre-season periods, daily creel limits, minimum sizes, and stretches designated catch and release or artificial lures only are all common, and they vary by individual waterbody rather than statewide.

None of that is guesswork. Every state wildlife agency publishes the current rules and the stocking schedule on the same site that sells the licence, which makes reading it the cheapest preparation available.