When people search for the largest gas utilities in the U.S., they usually mean the biggest local distribution companies (LDCs)—the regulated utilities that deliver natural gas to homes and businesses through local pipeline networks (not the producers or interstate pipeline operators).
One of the clearest ways to define largest is number of customers served. In this guide, the ranking below uses the American Gas Association (AGA) “2024 Ranking of Companies by Total Sales Customers” (latest available in the AGA’s annual utility rankings set).
What counts as a gas utility in this ranking?
A gas utility (LDC) is the company that:
- owns/operates the local distribution system,
- bills end-use customers (residential, commercial, industrial, etc.),
- is typically regulated by a state public utilities commission.
AGA’s utility rankings reflect Top local distribution companies and note that companies may report either at the corporate level or subsidiary level—AGA does not combine subsidiaries into corporate totals for these rankings.
Top 10 largest gas utilities in the U.S. by total customers
The table below lists the top 10 from AGA’s 2024 customer ranking (a common size metric for utilities because it reflects service footprint and infrastructure scale).
| Rank | Gas utility (as listed by AGA) | Total customers | Total volumes (Mcf) | Total revenue |
|---|---|---|---|---|
| 1 | Southern California Gas Company | 5,941,423 | 304,350,434 | $4,348,979,157 |
| 2 | Pacific Gas | 4,225,002 | 202,128,578 | $4,510,507,571 |
| 3 | Atmos Energy Corporation | 3,397,062 | 273,159,854 | $3,753,339,623 |
| 4 | CenterPoint Energy Entex | 2,300,974 | 106,428,670 | $1,477,468,496 |
| 5 | Southwest Gas Corporation | 2,235,116 | 122,136,779 | $2,249,966,288 |
| 6 | Nicor Gas | 2,077,447 | 214,330,881 | $1,842,190,111 |
| 7 | Public Service Electric & Gas Co (PSE&G) | 1,854,374 | 176,992,697 | $1,824,439,256 |
| 8 | Consumers Energy Company | 1,823,810 | 189,085,311 | $1,974,962,030 |
| 9 | Public Service Co of Colorado | 1,489,916 | 132,847,570 | $1,334,404,728 |
| 10 | DTE Gas Company | 1,243,321 | 121,878,541 | $1,352,123,791 |
How to interpret the columns
- Total customers = count of sales customers across sectors (residential + commercial + others reported).
- Total volumes (Mcf) = total natural gas sales volume, in thousand cubic feet.
- Total revenue = total sales revenue associated with those deliveries/sales.
Why largest by customers is useful
What it tells you well
- Network scale: more customers generally means broader local pipeline infrastructure, service territory, and operations footprint.
- Customer mix: large customer counts often imply heavy residential/commercial presence (even if industrial volumes vary).
What it doesn’t fully capture
- Industrial-heavy utilities can deliver huge volumes with fewer customers (one industrial customer can consume as much as thousands of homes).
- Pipeline and midstream companies may move massive gas volumes but have very few customers because their customers are shippers or counterparties—not end users.
That’s why AGA also publishes separate rankings by total sales volumes (another lens on largest).
A second lens: largest by total gas volumes (why your list may differ)
If you rank by total sales volumes, the list can shift—especially because some entities with very few customers can move extremely large volumes.
For example, in AGA’s 2024 Ranking of Companies by Total Sales Volumes, the #1 slot is Kinder Morgan Tejas Pipeline LLC by volume—yet it has only 86 customers listed in that table.
That’s a good reminder to define your largest metric clearly:
- Largest LDCs for households → rank by customers
- Largest gas-delivery entities overall → rank by volumes
Where the data comes from
AGA explains that its annual utility rankings are based on companies’ Annual Report of Gas Operations (ARGO) reporting and that companies can report at the corporate level or subsidiary level; AGA does not combine subsidiaries for ranking purposes.
If you want to cross-check utility-level gas deliveries and customers, the U.S. Energy Information Administration (EIA) maintains natural gas data resources and also references company-level statistics (including number of customers) from Form EIA-176 (not always as easy to browse as AGA’s ranking sheets, but useful for deeper analysis).
What these largest utilities typically have in common
Even though each company operates in different states and regulatory environments, the largest gas utilities often share:
- Dense or fast-growing service territories: More customers usually come from high-population metro regions or high-growth states.
- Large residential footprints: Residential service is typically the biggest driver of customer counts (even if industrial customers drive volume).
- Major investment in safety and pipe replacement programs: Larger systems mean ongoing capital programs for modernization and safety compliance.
- Scale advantages: Large utilities can spread certain operating costs across more customers—but local regulation, weather, and infrastructure age still heavily influence rates.
How to use this list
- If you’re researching service coverage, start with the customer-ranked top 10 (these utilities collectively serve tens of millions of customers).
- If you’re researching market impact (e.g., who moves the most gas), also look at volume rankings, which can include pipeline-focused entities.
- If you’re building a dataset or content cluster, structure related posts as:
- Largest gas utilities by customers
- Largest by sales volumes
- Top utilities by state
- Gas vs electric utility rankings
Conclusion
The top 10 largest gas utilities in the U.S. (by total sales customers) are led by Southern California Gas Company, followed by Pacific Gas, Atmos Energy, CenterPoint Energy Entex, Southwest Gas, Nicor Gas, PSE&G, Consumers Energy, Public Service Co of Colorado, and DTE Gas Company.
Note: This customer-based ranking is one of the most practical ways to define largest for end-use utility service—while volume-based rankings can tell a different story depending on how companies report and whether pipeline entities are included.