Permit or Not · All projects · Add a subpanel · Texas

Do I need a permit to add a subpanel in Texas?

Usually needs a permit

A subpanel means a new feeder and new distribution, not a repair — that is permit work essentially everywhere, and the inspection exists to catch one specific mistake.

How Texas decides

Code adoption
Mixed — state and local
Edition on file
2021 IRC
Local amendments
Permitted
Verified county offices
45 of Texas’s counties

Texas sits between the two models: parts of the state work from a state-level adoption and parts are left to local governments. In practice that means the answer depends on which office covers your address more than it does in a statewide state, and the only way to settle it is to ask the one that would issue the permit.

The edition on file for Texas is the 2021 IRC. Editions matter less than people expect for the exemption thresholds and more than people expect for how the work has to be built — and a jurisdiction that has not caught up to the state's edition is common rather than remarkable.

On file for Texas: Locals may be more current than the state; many counties have no residential code.

Adoption data from Code Adoption by State (Code Check), retrieved 2026-08-09, checked for Texas on 2026-08-09. That source gives the edition and whether adoption binds statewide. It does not give per-project thresholds, and neither do we — the thresholds on this page are the model code's. Code Adoption by State →

What changes the answer

These thresholds come from the model code. Texas lets its cities and counties amend the code they adopt, and an amended threshold is usually where people get caught.

Electrical permits are required under the adopted NEC / IRC Chapter 34; subpanels are not in the R105.2 exemption list. Neutrals and grounds must be separated downstream of the service disconnect — NEC Article 408 and 250.24(A)(5) — and a detached building fed by a feeder needs its own grounding electrode under NEC 250.32.

Why it matters

The mistake this inspection is looking for is neutrals and grounds bonded together in the subpanel. It works, everything turns on, and normal current now flows on the ground path and on any metal it touches — including the water pipes. Nothing about that is visible once the cover is back on.

Confirm the requirement with the Texas city or county building department that would issue the permit before you start.

Texas county building departments we have verified

Permits in Texas are issued by city and county building departments, not by the state. These 45 county permit pages have each been opened and checked, including a check that the page belongs to a county in Texas — one in ten links in our first pass was a building department in another state entirely, so every entry here names the wording that identified it.

County offices. If your address sits inside a city or town, the city issues the permit and the county page will send you back out again. Checked 2026-08-25. We can resolve a ZIP to a proven county page for 481 Texas ZIP codes; outside those, the checker falls back to a search rather than a guess.

This is the typical rule, not your answer

Nothing here is a permit decision, and it is not legal or engineering advice. No page can settle this for your address — permitting in Texas is run by individual city and county building departments, and the one that covers your property is the only one whose answer binds anyone. Put a ZIP in and we will name the office that decides, and show you the county permit page where we have proven one.

More on add a subpanel

The full add a subpanel guide covers why the thresholds sit where they do, what catches people, and the narrower versions of this question — extending rather than building, repairing rather than replacing, and the cases that sit right on a limit.

Add a subpanel in other states