Engineering firm COA: who needs one and how it works

Last checked Sep 29, 2026. State counts come from SealBench’s rule tables, which cite each board and aren’t yet confirmed with the boards; anything else is cited where it’s stated. Not legal advice.

Firm license vs individual license

The individual PE license belongs to the engineer and moves with them. The COA belongs to the firm and stays with it, but it usually names one or more licensed people in responsible charge. Where a COA is required, a sheet can’t go out under the firm’s name without one, however well licensed the engineer is.

Which states expect one

37 of the 51 jurisdictions in our data expect an engineering firm to hold a firm credential from the board, under different names: certificate of authorization, firm registration, business registration, firm license, or a firm disclosure filing. The by-state table lists them, and each state page quotes the rule we hold. Harbor Compliance’s engineering page counts 34 states that require a firm license and 8 more with other requirements; the two counts use different definitions.

Sole proprietors

Some states exempt an engineer practicing in their own name; others don’t. Tennessee, for example, says a sole proprietor practicing in their own name doesn’t file its firm disclosure (from our Tennessee rule table, not yet confirmed with the board). Check the state before assuming either way.

Board COA vs Secretary of State “certificate of authority”

A corporation or LLC formed in one state usually registers with the Secretary of State to do business in another, and that filing is often called a certificate of authority. It’s a different thing from the engineering board’s COA. Many firms need both, from two different offices.

Florida: a registry, not a COA

Florida no longer issues engineering-firm certificates of authorization. Firms that held one were rolled over into FBPE’s Engineering Business Registry, and a business offering engineering in Florida registers and must be qualified by a Florida-licensed PE, its qualifying agent (FBPE, read Sep 29, 2026).

The qualifier

Most COAs depend on a named licensed person. When that person leaves, or their license lapses, the COA can be at risk; see the qualifying engineer guide and COA and qualifier tracking.