There is no national license for tree care, and no federal safety standard written for it either. What a tree company must hold, and what its advertising must say, depends on the state and sometimes the city, and most of the rules were written in answer to complaints after storms.
Maryland. The tree expert law dates to 1945. Anyone who advertises or performs tree care for hire, removal included, needs a Tree Expert License, and every licensee must display the number on trucks, proposals, contracts and advertisements. A first offense is a misdemeanor with a fine of up to $500. After storms, the Department of Natural Resources warns residents about operators painting fraudulent license numbers on vehicles or calling themselves “bonded and insured”, and points them to its license search.
New Jersey. The Tree Expert and Tree Care Operators Licensing Act requires at least one licensed person in every company that hires itself out for tree care, sets minimum liability insurance, and includes rules on advertising properly. The state board says the act exists to address complaints about unqualified, uninsured or dishonest companies, especially after storms.
California. Since January 1, 2024, tree contractors can be licensed under the C-49 Tree and Palm classification, and every applicant sits a trade exam, because the state wanted tree contractors tested on health and safety. Holders of the older classifications may keep working under them, and incidental pruning by a gardener falls outside the C-49. From January 1, 2025 the minor-work exemption is $1,000, and unlicensed operators relying on it carry an advertising disclosure.
Cities. TCIA tells homeowners to ask city hall whether arborists need a local license, since many communities require one. Austin regulates trees from 8 inches in diameter on private property, requires a permit to remove a protected tree of 19 inches or more, and treats listed species from 24 inches as heritage trees.
Safety. OSHA still has no tree care standard. In June 2026 TCIA reported that OSHA’s construction advisory committee had unanimously recommended writing one, and that OSHA frequently relies on ANSI Z133, now in its 2026 edition.
For the marketing, that comes down to three habits. Put the license number wherever your state wants it, which in Maryland means every ad. Say who on the crew holds which credential, and link the directory that proves it. And keep every claim to something a buyer can check, because the state is telling the buyer to check.