UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 10-Q/A

For the quarterly period ended September 30, 2014

OR

For the transition period from                      to                     .

Commission file number: 000-55336

NATIONAL COMMERCE CORPORATION

(Exact name of registrant as specified in its charter)

(205) 313-8100

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  ¨    No  x

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.

EXPLANATORY NOTE

The sole purpose of this Amendment No. 1 to the Quarterly Report of National Commerce Corporation (the “Company”) on Form 10-Q for the quarterly period ended September 30, 2014, filed with the Securities and Exchange Commission on December 8, 2014 (the “Form 10-Q”), is to file Exhibit 101 to the Form 10-Q in accordance with Rule 405 of Regulation S-T. Exhibit 101 to this report provides the Interactive Data Files for the unaudited consolidated financial statements and related notes from the Form 10-Q formatted in XBRL (eXtensible Business Reporting Language). As permitted by Rule 405(a)(2)(ii) of Regulation S-T, Exhibit 101 was required to be filed by amendment within 30 days of the original filing date of the Form 10-Q.

Other than the aforementioned, no other changes have been made to the Form 10-Q. This Amendment No. 1 to the Form 10-Q speaks as of the original filing date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date, and does not modify or update in any way disclosures made in the original Form 10-Q.

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PART II — OTHER INFORMATION

Item 6. Exhibits

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

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