UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 19, 2012

Discover Card Execution Note Trust

(Exact name of issuing entity in respect of the notes as specified in charter)

Discover Card Master Trust I

(Exact name of issuing entity in respect of the Series 2007-CC Collateral Certificate as specified in charter)

Discover Bank

(Exact name of sponsor and depositor as specified in charter)

Registrant’s Telephone Number, including area code: (302) 323-7315

Former name or former address, if changed since last report: Not Applicable

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Class B(2012-3) Notes. On November 19, 2012, Discover Card Execution Note Trust entered into the Class B(2012-3) Terms Document, dated as of November 19, 2012 (the “Class B(2012-3) Terms Document”), between Discover Card Execution Note Trust, as Issuer, and U.S. Bank National Association, as Indenture Trustee. An unexecuted copy of the Class B(2012-3) Terms Document was filed as Exhibit 4.1 to Discover Card Execution Note Trust’s Current Report on Form 8-K filed on November 16, 2012.

Class C(2012-3) Notes. On November 19, 2012, Discover Card Execution Note Trust entered into the Class C(2012-3) Terms Document, dated as of November 19, 2012 (the “Class C(2012-3) Terms Document”), between Discover Card Execution Note Trust, as Issuer, and U.S. Bank National Association, as Indenture Trustee.

Issuance of Class B(2012-3) Notes. On November 19, 2012, Discover Card Execution Note Trust issued $250,000,000 principal amount of DiscoverSeries Class B(2012-3) Notes (the “Class B(2012-3) Notes”) pursuant to the Indenture, dated as of July 26, 2007, as amended by the First Amendment to Indenture, dated as of June 4, 2010, and as supplemented by the Amended and Restated Indenture Supplement, dated as of June 4, 2010, each between Discover Card Execution Note Trust, as Issuer, and U.S. Bank National Association as Indenture Trustee (as so amended and supplemented, the “Indenture”), and the Class B(2012-3) Terms Document. In connection with this issuance, the investor interest in receivables represented by the collateral certificate issued by the Discover Card Master Trust I that secures the DiscoverSeries Notes was increased by $250,000,000. Discover Card Execution Note Trust paid the net proceeds from the issuance to Discover Bank in exchange for the increase in the investor interest in receivables represented by the collateral certificate.

Unregistered Sale of Class C(2012-3) Notes. On November 19, 2012, Discover Card Execution Note Trust sold $265,000,000 principal amount of the DiscoverSeries Class C(2012-3) Notes (the “Class C(2012-3) Notes”) in reliance upon the exemption contained in Section 4(2) of the Securities Act of 1933, as amended. The Class C(2012-3) Notes were sold at a discount for $260,484,665, with no applicable underwriting discounts or commissions, and will not bear interest prior to their expected maturity. The Class C(2012-3) Notes were issued pursuant to the Indenture and the Class C(2012-3) Terms Document. In connection with this issuance, the investor interest in receivables represented by the collateral certificate issued by the Discover Card Master Trust I that secures the DiscoverSeries Notes was increased by $265,000,000. Discover Card Execution Note Trust paid the net proceeds from the issuance to Discover Bank in exchange for the increase in the investor interest in receivables represented by the collateral certificate.

Increase in Principal Amount of Class D(2009-1) Notes. On November 19, 2012, Discover Bank, pursuant to Section 2.03 of the Note Purchase Agreement (the “Note Purchase Agreement”), dated as of July 2, 2009, among Discover Card Execution Note Trust, as Issuer, Discover Bank, as Depositor, and the purchasers named therein and Section 2.06 of the Class D(2009-1) Terms Document, dated as of July 2, 2009, as the same may be further amended,

supplemented, restated, amended and restated, replaced or otherwise modified from time to time, by and between Discover Card Execution Note Trust, as Issuer, and U.S. Bank National Association as Indenture Trustee, increased the Outstanding Dollar Principal Amount of the Class D(2009-1) Notes. The increase in the Outstanding Dollar Principal Amount of the Class D(2009-1) Notes was in the amount of $70,227,273, resulting in an Outstanding Dollar Principal Amount of the Class D(2009-1) Notes of $2,248,636,364. The Class D(2009-1) Notes were sold to purchasers in reliance upon the exemption contained in Section 4(2) of the Securities Act of 1933, as amended. The Notes were sold at par value for cash, with no applicable underwriting discounts or commissions. In connection with this increase, the investor interest in receivables represented by the collateral certificate issued by the Discover Card Master Trust I that secures the DiscoverSeries Notes was increased by $70,227,273. Discover Card Execution Note Trust paid the net proceeds from the issuance to Discover Bank in exchange for the increase in the investor interest in receivables represented by the collateral certificate.

Extension of Expected Maturity Date and Legal Maturity Date of Class D(2009-1) Notes. On November 19, 2012, Discover Bank, as Calculation Agent on behalf of Discover Card Execution Note Trust, extended the expected maturity date of the Class D(2009-1) Notes to July 15, 2019 and extended the legal maturity date of the Class D(2009-1) Notes to January 18, 2022.

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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