commercial paper notes (the “ECP Notes” and, together with the USCP Notes, “Commercial Paper”), which are guaranteed by the Company and are to be issued outside of the United States. The maturities of the ECP Notes will vary, but may not exceed 183 days from the date of issue. The ECP Notes are sold under customary terms in the commercial paper market and may be issued at par or a discount therefrom or a premium thereto and bear varying interest rates on a fixed or floating basis. The ECP Notes may be issued in Euros, Sterling, U.S. dollars or other currencies. The maximum aggregate principal amount outstanding of ECP Notes at any time is $2,000.0. As of September 30, 2021, there were 0 ECP Notes outstanding.
Amounts available under the Commercial Paper Programs may be borrowed, repaid and re-borrowed from time to time. In conjunction with the Revolving Credit Facility, the authorization from the Company’s Board of Directors limits the maximum principal amount outstanding of USCP Notes, ECP Notes, and any other commercial paper or similar programs, along with outstanding amounts under the Revolving Credit Facility, at any time to $2,500.0 in the aggregate. The Commercial Paper Programs are rated A-2 by Standard & Poor’s and P-2 by Moody’s and are currently backstopped by the Revolving Credit Facility, as amounts undrawn under the Company’s Revolving Credit Facility are available to repay Commercial Paper, if necessary. Net proceeds of the issuances of Commercial Paper are expected to be used for general corporate purposes. The Commercial Paper is classified as long-term debt in the accompanying Condensed Consolidated Balance Sheets since the Company has the intent and ability to refinance the Commercial Paper on a long-term basis using the Company’s Revolving Credit Facility. The Commercial Paper is actively traded and is therefore classified as Level 1 in the fair value hierarchy (Note 5). The carrying value of Commercial Paper borrowings approximates their fair value.
U.S. Senior Notes
On September 14, 2021, the Company issued $750.0 principal amount of unsecured 2.200% Senior Notes due September 15, 2031 at 99.634% of face value (the “2031 Senior Notes”). The 2031 Senior Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. Interest on the 2031 Senior Notes is payable semiannually on March 15 and September 15 of each year, commencing on March 15, 2022. Prior to June 15, 2031, the Company may, at its option, redeem some or all of the 2031 Senior Notes at any time by paying the redemption price (which may include a make-whole premium), plus accrued and unpaid interest, if any, to, but not including, the date of redemption. If redeemed on or after June 15, 2031, the Company may, at its option, redeem some or all of the 2031 Senior Notes at any time by paying the redemption price equal to 100% of the principal amount thereof, plus accrued and unpaid interest, if any, to, but not including, the date of redemption. The Company used the net proceeds from the 2031 Senior Notes to repay certain outstanding borrowings under the U.S. Commercial Paper Program.
On February 20, 2020, the Company issued $400.0 principal amount of unsecured 2.050% Senior Notes due March 1, 2025 at 99.829% of face value (the “2025 Senior Notes”). The 2025 Senior Notes are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. Interest on the 2025 Senior Notes is payable semiannually on March 1 and September 1 of each year, commencing on September 1, 2020. Prior to February 1, 2025, the Company may, at its option, redeem some or all of the 2025 Senior Notes at any time by paying the redemption price (which may include a make-whole premium), plus accrued and unpaid interest, if any, to, but not including, the date of redemption. If redeemed on or after February 1, 2025, the Company may, at its option, redeem some or all of the 2025 Senior Notes at any time by paying the redemption price equal to 100% of the principal amount thereof, plus accrued and unpaid interest, if any, to, but not including, the date of redemption. On April 1, 2020, the Company used the net proceeds from the 2025 Senior Notes to repay the $400.0 principal amount of unsecured 2.20% Senior Notes due April 1, 2020 upon maturity.
All of the Company’s outstanding senior notes in the United States (the “U.S. Senior Notes”) are unsecured and rank equally in right of payment with the Company’s other unsecured senior indebtedness. Interest on each series of U.S. Senior Notes is payable semiannually. The Company may, at its option, redeem some or all of any series of U.S. Senior Notes at any time subject to certain terms and conditions, which include paying 100% of the principal amount, plus accrued and unpaid interest, if any, to the date of redemption, and, with certain exceptions, a make-whole premium. The fair value of each series of U.S. Senior Notes is based on recent bid prices in an active market and is therefore classified as Level 1 in the fair value hierarchy (Note 5). The remaining principal amount outstanding associated with