Core gas customers, who are typically residential and small business customers, are directly connected to their utility’s pipeline where they receive natural gas. However, as a core customer, the California Legislature, and the California Public Utilities Commission (CPUC) allows you to choose your natural gas supplier: either the utility or a Core Transport Agent (CTA). CTAs are non-utility businesses and are not subject to the same regulations as your public utility. They provide an alternative source of gas supply and may provide alternatives in how that gas is priced. In order to provide service to core gas customers, a CTA must register with the CPUC. As part of that registration, it must provide evidence of its operational and technical abilities and its financial health. CTAs currently registered with the CPUC may be found on the CPUC website at Core Transport Agents (CTAs) - List and Registration.

No matter whom you choose to supply your natural gas, the utility will still deliver it. If you choose a CTA, the utility will still charge gas delivery fees, while the CTA will charge you for the cost of the gas and any other fees for their service. Your bill might come from the utility, the CTA, or both.

The cost of gas from a CTA and all other fees should be provided for you to review prior to starting CTA service. This information should be in writing and in your preferred language so that you can compare gas prices between the utility and the CTA. The CPUC does not regulate the rates or fees charged by CTAs. Some recurring fees from CTAs may include administrative fees, monthly fees, carbon-offsetting fees, and late-payment fees or taxes. Before you sign a contract, be sure to review the contract terms, length, and any early termination fees.

Some CTAs offer fixed or variable rate natural gas pricing as part of your total cost. The table below will help you understand the basic differences between the two methods:

Fixed Rate

Variable Rate

A price per therm of gas that will remain the same throughout the contract term.

A price per therm of gas that can change over the term of the contract. CTAs are not required to list the price but must provide an estimate and illustrate how your bill varies with increased usage.

If the market price of gas falls, you may have to wait until your contract expires to get a lower rate.

If the market price of gas rises, your rate may increase. If the market price drops, your rate may decrease.

Extreme temperatures will not change your per therm rate. However, your natural gas usage may change and affect your bill.

Extreme temperatures can affect market prices, which may increase your per therm rate. These extremes may also affect your natural gas usage and bill.


Remember, you have no obligation to switch your natural gas supplier: it is your choice. A CTA may contact you directly, or you may refer to the list of registered CTAs on the CPUC’s website if you are interested in switching. If a CTA contacts you and you decide to switch, a third-party verification company not associated with the CTA must verify your consent to switch.

To compare the available CTAs in your area, visit or CTA Cost Comparison page.

To see a list of CTAs who have received citations from the CPUC’s Utility Enforcement Branch, visit: UEB Citations-Fines-Restitutions -- Active.xlsx (

If you believe you were switched to a CTA without your consent, or that you are being charged new or undisclosed fees by a CTA, you can contact the CPUC’s Consumer Affairs Branch:

  • Online at;
  • By phone at 1-800-649-7570 (Monday-Friday, 8:30 a.m.– 4:30 p.m.); or
  • By mail at: California Public Utilities Commission

Consumer Affairs Branch
505 Van Ness Avenue
San Francisco, CA  94102

CTA Consumer Guide

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