Form of Floating Rate Notes Officers Certificate, to be dated March 9, 2021

Exhibit 4.2

ATMOS ENERGY CORPORATION

Officers’ Certificate Pursuant to Section 301 of the Indenture

March 9, 2021

Each of the undersigned, Daniel M. Meziere, Vice President of Investor Relations and Treasurer, and Karen E. Hartsfield, Senior Vice President, General Counsel and Corporate Secretary of Atmos Energy Corporation (the “Company”) certifies, pursuant to the authority delegated to each of them, as an officer of the Company, pursuant to the resolutions adopted by the board of directors of the Company (the “Board”) on February 26, 2021 (copies of which resolutions are attached hereto as Exhibit I), that pursuant to Section 301 of the Indenture dated as of March 26, 2009 (the “Indenture”) between the Company and U.S. Bank National Association, as trustee (the “Trustee”), a series of debt securities of the Company is hereby established with the following terms and provisions (unless otherwise defined herein, capitalized terms used herein have the meaning given thereto in the Indenture):

1. The title of the series of the securities to be issued is the Floating Rate Senior Notes due 2023 (the “Notes”).

2. The Notes are unsubordinated and will rank equally with all of the Company’s other unsecured and unsubordinated debt. Subordinated debt will rank junior to the Notes and the Company’s other senior debt.

3. The aggregate principal amount of the Notes that initially may be issued under the Indenture, in connection with the Underwriting Agreement, dated as of March 4, 2021, among the Company and certain underwriters named therein, is $1,100,000,000, and the Stated Maturity of the Notes is March 9, 2023. The Notes shall be offered to the public at a price representing 100.000% of their principal amount.

4. The Company will pay interest quarterly on the Notes at the Three-Month LIBOR Rate plus 38 basis points (0.380%) per year (the “Margin”), reset quarterly, subject to the provisions set forth herein. The interest rate for the initial interest period is 0.56538%. The Company will pay interest on March 9, June 9, September 9 and December 9 of each year, each such date referred to as an “Interest Payment Date,” and also a “LIBOR Rate Reset Date,” until maturity or earlier redemption. The first Interest Payment Date and first LIBOR Rate Reset Date will be June 9, 2021. The record date for interest payable on any Interest Payment Date shall be the close of business on (1) the business day immediately preceding such Interest Payment Date so long as all of the Notes remain in book-entry only form, or (2) the 15th calendar day immediately preceding such Interest Payment Date if any of the Notes do not remain in book-entry only form. Interest on the Notes will accrue from and including the date of original issuance to but excluding the first Interest Payment Date. Starting on the first Interest Payment Date, interest on each Note will accrue from and including the last Interest Payment Date to which the Company has paid, or duly provided for the payment of, interest on that Note to but excluding the next succeeding Interest Payment Date. No interest will accrue on the Notes for the day on which the Notes mature.

The Notes will bear interest for each interest period at a rate determined by the Calculation Agent, except as set forth below. Promptly upon determination, the Calculation Agent will inform the Trustee and the Company, or, in certain circumstances described below, the Company or its designee will inform the Trustee, of the interest rate for the next interest period.

The interest rate will be reset on the LIBOR Rate Reset Date and will be the interest rate applicable from such LIBOR Rate Reset Date (or, in the case of any day preceding the first LIBOR Rate Reset Date, the interest rate determined as described below on March 5, 2021) to the next succeeding LIBOR Rate Reset Date. The amount of interest payable for any interest period on the Notes will be determined by the Company and will be computed by multiplying the floating rate for that interest period by a fraction, the numerator of which will be the actual number of days elapsed during that interest period (determined by including the first day of the interest period and excluding the last day), and the denominator of which will be 360, and by multiplying the result by the aggregate principal amount of the Notes. The interest rate for any interest period will at no time be higher than the maximum rate then permitted by applicable law. Additionally, the interest rate will in no event be lower than zero.

If an Interest Payment Date, other than a redemption date or the maturity date of the Notes, falls on a day that is not a business day, the Interest Payment Date will be postponed to the next day that is a business day, except that if that business day is in the next succeeding calendar month, the Interest Payment Date will be the immediately preceding business day. Also, if a redemption date or the maturity date of the Notes falls on a day that is not a business day, then payment of the interest or principal payable on that date will be made on the next succeeding day which is a business day, and no interest will be paid or other payment made in respect of such delay. A “business day” is any day that is not a Saturday, a Sunday, or a day on which banking institutions or trust companies in New York City are generally authorized or required by law or executive order to remain closed.

If any LIBOR Rate Reset Date falls on a day that is not a business day, the LIBOR Rate Reset Date will be postponed to the next day that is a business day, except that if that business day is in the next succeeding calendar month, the LIBOR Rate Reset Date will be the immediately preceding business day.

The “Three-Month LIBOR Rate” for each interest period beginning on a LIBOR Rate Reset Date, or March 9, 2021 in the case of the initial interest period, means the rate determined in accordance with the following provisions:

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The Calculation Agent shall not have any liability for (x) the selection of major reference banks in the London Inter-Bank Market or major banks in New York City used for purposes of calculating the Three-Month LIBOR Rate, or for the failure or unwillingness of any major reference banks in the London Inter-Bank Market or major banks in New York City to provide a quotation or (y) any quotations received from such major reference banks in the London Inter-Bank Market or major banks in New York City, as applicable. For the avoidance of doubt, if the rate appearing on the Bloomberg L.P. page “BBAM” or Reuters Page LIBOR01 for the Three-Month LIBOR Rate is unavailable, neither the Calculation Agent nor the Trustee shall be under any duty or obligation to take any action other than the Calculation Agent’s obligation to take the actions expressly set forth herein and in the Indenture, in each case whether or not quotations are provided by such major reference banks in the London Inter-Bank Market or major banks in New York City, as applicable. The Calculation Agent will not be obliged to solicit rates if it receives no quotations for three (3) consecutive London Business Days or if the Three-Month LIBOR Rate (or other applicable Benchmark) has been disrupted permanently or indefinitely.

Notwithstanding clause (1) and clause (2) in the preceding paragraph, if the Company (or its designee) determine on or prior to the relevant LIBOR Interest Determination Date that a Benchmark Transition Event and its related Benchmark Replacement Date (each, as defined herein) have occurred with respect to Three-Month LIBOR (or the then-current Benchmark, as applicable), then the provisions set forth below under “Effect of

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Benchmark Transition Event,” which are referred to as the benchmark transition provisions, will thereafter apply to all determinations of the rate of interest payable on the Notes. In accordance with the benchmark transition provisions, after a Benchmark Transition Event and its related Benchmark Replacement Date have occurred, the amount of interest that will be payable for each interest period will be an annual rate equal to the sum of the Benchmark Replacement (as defined herein) and the Margin specified herein. In the event that LIBOR or applicable Benchmark is not available on any determination date, then unless the Calculation Agent is notified of a replacement benchmark in accordance with the terms of Notes within three (3) London Business Days, the Calculation Agent shall use the interest rate in effect for the immediately prior interest period.

All percentages resulting from any calculation of any interest rate for the Notes will be rounded, if necessary, to the nearest one hundred-thousandth of a percentage point, with five one-millionths of a percentage point rounded upwards (e.g., 3.456789% (or .03456789) being rounded to 3.45679% (or .0345679)) and all dollar amounts used in or resulting from such calculations will be rounded to the nearest cent (with one-half cent being rounded upwards). Any percentage resulting from any calculation of any interest rate for the Notes less than 0.00% will be deemed to be 0.00% (or .0000).

As used herein:

“Calculation Agent” means a banking institution or trust company appointed by the Company to act as calculation agent, initially U.S. Bank National Association.

“LIBOR Business Day” means any day on which dealings in deposits in U.S. Dollars are transacted in the London Inter-Bank Market.

“LIBOR Interest Determination Date” means (i) the second LIBOR Business Day preceding each LIBOR Rate Reset Date or (ii) March 5, 2021 in the case of the initial interest period.

“London Business Day”, means any day that, in the city of the principal Corporate Trust Office of the Trustee and in London, is neither a Saturday, Sunday, or legal holiday nor a day on which banking institutions are authorized or required by law or regulation to close.

Absent willful misconduct, bad faith or manifest error, the calculation of the applicable interest rate for each interest period by the Calculation Agent, or in certain circumstances described below, by the Company or its designee will be final and binding on the Company, the Trustee, and the holders of the Notes.

Neither the Trustee, paying agent nor Calculation Agent shall be under any obligation (i) to monitor, determine or verify the unavailability or cessation of the Three-Month LIBOR Rate (or other applicable Benchmark), or whether or when there has occurred, or to give notice to any other transaction party of the occurrence of, any Benchmark Transition Event or Benchmark Replacement Date, (ii) to select, determine or designate any alternative reference rate or Benchmark Replacement, or other successor or

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replacement benchmark index, or whether any conditions to the designation of such a rate have been satisfied, or (iii) to select, determine or designate any Benchmark Replacement Adjustment, or other modifier to any replacement or successor index, or (iv) to determine whether or what Benchmark Replacement Conforming Changes are necessary or advisable, if any, in connection with any of the foregoing. Neither the Trustee, paying agent, nor Calculation Agent shall be liable for any inability, failure or delay on its part to perform any of its duties set forth herein and in the Indenture as a result of the unavailability of the Three-Month LIBOR Rate (or other applicable Benchmark) and absence of a designated replacement Benchmark, including as a result of any inability, delay, error or inaccuracy on the part of any other transaction party, including without limitation the Company, in providing any direction, instruction, notice or information required or contemplated herein and in the Indenture and reasonably required for the performance of such duties. Neither the Trustee nor the Calculation Agent shall have any liability for any interest rate published by any publication that is the source for determining the interest rates of the Notes, including but not limited to the Reuters Screen (or any successor source) or Bloomberg L.P. page “BBAM” or Reuters Page LIBOR01 or for any rates compiled by the ICE Benchmark Administration or any successor thereto, or for any rates published on any publicly available source, including without limitation the Federal Reserve Bank of New York’s Website, or in any of the foregoing cases for any delay, error or inaccuracy in the publication of any such rates, or for any subsequent correction or adjustment thereto.

Any determination, decision or election that may be made by the Company or its designee in connection with a Benchmark Transition Event or a Benchmark Replacement, including any determination with respect to a rate or adjustment or of the occurrence or non-occurrence of an event, circumstance or date and any decision to take or refrain from taking any action or any selection, will be conclusive and binding absent manifest error, may be made in the Company’s or its designee’s sole discretion, and, notwithstanding anything to the contrary in the transaction documents, will become effective without consent from any other party. Neither the Trustee nor the Calculation Agent will have any liability for any determination made by or on behalf of the Company or its designee in connection with a Benchmark Transition Event or a Benchmark Replacement.

Benchmark Replacement. If the Company (or its designee) determine that a Benchmark Transition Event and its related Benchmark Replacement Date have occurred prior to the Reference Time in respect of any determination of the Benchmark on any date, the Benchmark Replacement will replace the then-current Benchmark for all purposes relating to the Notes in respect of such determination on such date and all determinations on all subsequent dates.

Benchmark Replacement Conforming Changes. In connection with the implementation of a Benchmark Replacement, the Company (or its designee) will have the right to make Benchmark Replacement Conforming Changes from time to time, except to the extent that such changes would increase or materially change or affect the duties, obligations or liabilities of the Calculation Agent (including without limitation the imposition or expansion of discretionary authority), or reduce, eliminate, limit or otherwise change any right, privilege or protection of the Calculation Agent, or would otherwise materially and adversely affect the Calculation Agent, in each case in its reasonable judgment, without such party’s express written consent.

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Decisions and Determinations. Any determination, decision or election that may be made by the Company (or its designee) pursuant to this subsection “Effect of Benchmark Transition Event,” including any determination with respect to tenor, rate or adjustment or of the occurrence or non-occurrence of an event, circumstance or date and any decision to take or refrain from taking any action or any selection, will be conclusive and binding absent manifest error, will be made in the Company’s (or its designee’s) sole discretion, and, notwithstanding anything to the contrary in the documentation relating to the Notes, shall become effective without consent from any other party.

As used in this subsection:

“Benchmark” means, initially, the Three-Month LIBOR Rate; provided that if a Benchmark Transition Event and its related Benchmark Replacement Date have occurred with respect to the Three-Month LIBOR Rate or the then-current Benchmark, then “Benchmark” means the applicable Benchmark Replacement.

“Benchmark Replacement” means the Interpolated Benchmark with respect to the then-current Benchmark, plus the Benchmark Replacement Adjustment for such Benchmark; provided that if the Company (or its designee) cannot determine the Interpolated Benchmark as of the Benchmark Replacement Date, then “Benchmark Replacement” means the first alternative set forth in the order below that can be determined by the Company (or its designee) as of the Benchmark Replacement Date:

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“Benchmark Replacement Adjustment” means the first alternative set forth in the order below that can be determined by the Company (or its designee) as of the Benchmark Replacement Date:

The Benchmark Replacement Adjustment shall not include the Margin specified herein and such Margin shall be applied to the Benchmark Replacement to determine the interest payable on the Notes.

“Benchmark Replacement Conforming Changes” means, with respect to any Benchmark Replacement, any technical, administrative or operational changes (including changes to the definition of “interest period,” timing and frequency of determining rates and making payments of interest, rounding of amounts or tenor, and other administrative matters) that the Company (or its designee) decide may be appropriate to reflect the adoption of such Benchmark Replacement in a manner substantially consistent with market practice (or, if the Company (or its designee) decide that adoption of any portion of such market practice is not administratively feasible or if the Company (or its designee) determine that no market practice for use of the Benchmark Replacement exists, in such other manner as the Company (or its designee) determine is reasonably necessary).

“Benchmark Replacement Date” means the earliest to occur of the following events with respect to the then- current Benchmark:

For the avoidance of doubt, if the event giving rise to the Benchmark Replacement Date occurs on the same day as, but earlier than, the Reference Time in respect of any determination, the Benchmark Replacement Date will be deemed to have occurred prior to the Reference Time for such determination.

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“Benchmark Transition Event” means the occurrence of one or more of the following events with respect to the then-current Benchmark:

“Compounded SOFR” means the compounded average of SOFRs for the applicable Corresponding Tenor, with the rate, or methodology for this rate, and conventions for this rate (which, for example, may be compounded in arrears with a lookback and/or suspension period as a mechanism to determine the interest amount payable prior to the end of each interest period or compounded in advance) being established by the Company (or its designee) in accordance with:

For the avoidance of doubt, the calculation of Compounded SOFR shall exclude the Benchmark Replacement Adjustment and the Margin specified herein.

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“Corresponding Tenor” with respect to a Benchmark Replacement means a tenor (including overnight) having approximately the same length (disregarding business day adjustment) as the applicable tenor for the then-current Benchmark.

“Federal Reserve Bank of New York’s Website” means the website of the Federal Reserve Bank of New York at http://www.newyorkfed.org, or any successor source.

“Interpolated Benchmark” with respect to the Benchmark means the rate determined for the Corresponding Tenor by interpolating on a linear basis between: (1) the Benchmark for the longest period (for which the Benchmark is available) that is shorter than the Corresponding Tenor and (2) the Benchmark for the shortest period (for which the Benchmark is available) that is longer than the Corresponding Tenor.

“ISDA Definitions” means the 2006 ISDA Definitions published by the International Swaps and Derivatives Association, Inc. or any successor thereto, as amended or supplemented from time to time, or any successor definitional booklet for interest rate derivatives published from time to time.

“ISDA Fallback Adjustment” means the spread adjustment (which may be a positive or negative value or zero) that would apply for derivatives transactions referencing the ISDA Definitions to be determined upon the occurrence of an index cessation event with respect to the Benchmark for the applicable tenor.

“ISDA Fallback Rate” means the rate that would apply for derivatives transactions referencing the ISDA Definitions to be effective upon the occurrence of an index cessation date with respect to the Benchmark for the applicable tenor excluding the applicable ISDA Fallback Adjustment.

“Reference Time” with respect to any determination of the Benchmark means (1) if the Benchmark is the Three-Month LIBOR Rate, 11:00 a.m., London time, on the LIBOR Interest Determination Date, and (2) if the Benchmark is not the Three-Month LIBOR Rate, the time determined by the Company (or its designee) in accordance with the Benchmark Replacement Conforming Changes.

“Relevant Governmental Body” means the Federal Reserve Board and/or the Federal Reserve Bank of New York, or a committee officially endorsed or convened by the Federal Reserve Board and/or the Federal Reserve Bank of New York or any successor thereto.

“SOFR” with respect to any day means the secured overnight financing rate published for such day by the Federal Reserve Bank of New York, as the administrator of the benchmark (or a successor administrator), on the Federal Reserve Bank of New York’s Website.

“Term SOFR” means the forward-looking term rate for the applicable Corresponding Tenor based on SOFR that has been selected or recommended by the Relevant Governmental Body.

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“Unadjusted Benchmark Replacement” means the Benchmark Replacement excluding the Benchmark Replacement Adjustment.

5. Payment of the principal of (and premium, if any) and interest on the Notes will be made at the office or agency of the Company maintained for that purpose in the Borough of Manhattan, the City of New York, or at such other office or agency of the Company as may be maintained for such purpose, in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts. So long as the Notes remain in book-entry form, all payments of principal and interest will be made by the Company in immediately available funds.

6. The Company may redeem the Notes prior to maturity at the Company’s option, at any time on or after September 9, 2021, in whole or from time to time in part. The Redemption Price will be equal to 100% of the principal amount of the Notes to be redeemed, plus accrued and unpaid interest thereon, if any, to, but excluding, the Redemption Date.

In the case of a partial redemption of the Notes, the Notes to be redeemed shall be selected by the Trustee in accordance with the procedures of the Depository from the outstanding Notes not previously called for redemption. Notice of any redemption will be mailed by first class mail at least 15 days but not more than 60 days before the Redemption Date to each Holder of the Notes to be redeemed at its registered address. If any Notes are to be redeemed in part only, the notice of redemption will state the portion of the principal amount of the Notes to be redeemed. A new Note in a principal amount equal to the unredeemed portion of the Note will be issued in the name of the Holder of the Note upon surrender for the cancellation of the original Note. A partial redemption will not reduce the portion of any Note not being redeemed to a principal amount of less than $2,000. Unless the Company defaults in payment of the Redemption Price, on and after the Redemption Date, interest will cease to accrue on the Notes or the portions of the Notes called for redemption.

7. Section 703 of the Indenture is replaced with the following in its entirety for purposes of the Notes only:

The Company shall:

(1) file with the Trustee, within 30 days after the Company has filed the same with the Commission, unless such reports are available on the Commission’s EDGAR filing system (or any successor thereto), copies of the annual reports and of the information, documents and other reports (or copies of such portions of any of the foregoing as the Commission may from time to time by rules and regulations prescribe), which the Company may be required to file with the Commission pursuant to Section 13 or Section 15(d) of the Exchange Act; or, if the Company is not required to file information, documents or reports pursuant to either of such Sections, then the Company shall file with the Trustee and the Commission, in accordance with rules and regulations prescribed from time to time by the Commission, such of the supplementary and periodic information, documents and reports which may be required pursuant to Section 13 of the Exchange Act in respect of a security listed and registered on a national securities exchange as may be prescribed from time to time in such rules and regulations;

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(2) file with the Trustee and the Commission, in accordance with rules and regulations prescribed from time to time by the Commission, such additional information, documents and reports with respect to compliance by the Company with the conditions and covenants of this Indenture as may be required from time to time by such rules and regulations; and

(3) transmit to all Holders, as their names and addresses appear in the Security Register, within 30 days after the filing thereof with the Trustee, in the manner and to the extent provided in TIA Section 313(c), such summaries of any information, documents and reports required to be filed by the Company pursuant to Subsections (1) and (2) of this Section 703 as may be required by rules and regulations prescribed from time to time by the Commission.

8. The Company has no obligation to redeem, purchase or repay the Notes pursuant to any mandatory redemption or sinking fund or analogous provisions or at the option of the Holder thereof.

9. The entire principal amount of the Notes shall be payable upon declaration of acceleration of the Maturity of the Notes pursuant to the Indenture.

10. The defeasance and covenant defeasance provisions of Article Fourteen of the Indenture shall apply to the Notes.

11. The Trustee, the initial Calculation Agent, the initial Paying Agent and the initial Security Registrar for the Notes shall be U.S. Bank National Association. The Security Register for the Notes shall be initially maintained at, and the place where such Notes may be surrendered for registration of transfer or exchange shall be, the Trustee’s Corporate Trust Office located at 1349 West Peachtree Street, Suite 1050, Atlanta, Georgia 30309.

12. The Notes will be issued in registered permanent global form and evidenced by global securities (the “Global Securities”) in substantially the form attached hereto as Exhibit II with such appropriate insertions, omissions, substitutions and other variations as are required or permitted by the Indenture, and may have imprinted or otherwise reproduced thereon such legend or legends or endorsements, not inconsistent with the provisions of the Indenture, as may be required to comply with any law or with any rules or regulations pursuant thereto, or with any rules of any securities exchange or to conform to general usage, all as may be determined by the officers executing the Global Securities, as evidenced by their execution of such Global Securities. The beneficial owners of interests in the Global Securities may exchange such interests for Notes in certificated form (the “Definitive Notes”) only in limited circumstances as provided in the Indenture. In the event that Definitive Notes are issued in exchange for a Global Security, the form of certificate evidencing each Definitive Note shall be in substantially the form of the attached Global Securities, with such changes as are necessary to evidence the Notes in definitive form rather than as a Global Security. The Company initially appoints DTC to act as Depository with respect to the Notes.

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13. The Notes are issuable in denominations of $2,000 and any integral multiples of $1,000 in excess thereof.

14. The Events of Default set forth in the Indenture shall apply to the Notes.

15. The Company will not pay Additional Amounts on the Notes held by any Holder who is not a United States person in respect of any tax, assessment or governmental charge withheld or deducted.

16. The Company may, at any time, without the consent of the Holders of the Notes, create and issue additional securities having the same ranking, interest rate, maturity and other terms as the Notes. Any such additional securities shall be consolidated and form the same series of the Notes having the same terms as to status, redemption and otherwise as the Notes under the Indenture.

Each of us further certifies that the form and terms of the Notes as established in this certificate have been established pursuant to Section 301 of the Indenture and comply with the Indenture.

[Signature page follows]

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IN WITNESS WHEREOF, I have executed this certificate as of the date first written above.

IN WITNESS WHEREOF, I have executed this certificate as of the date first written above.

Officers’ Certificate Pursuant to Section 301 of the Indenture