At March 31, 2022, we carried a total debt balance (including accrued interest) of €5,529.9 million, of which €1,442.4 million principal amount is related to the € and USD-denominated Senior Secured Fixed Rate Notes due March 2028 and €3,180.9 million principal amount is owed under our 2020 Amended Senior Credit Facility with maturities ranging from April 2028 through April 2029. Our total debt balance at March 31, 2022 also included a principal amount of €338.9 million related to our vendor financing program, while the remainder primarily represents lease obligations associated with the Interkabel Acquisition and other leases.
At March 31, 2022, we carried €338.9 million of short-term debt related to our vendor financing program, all of which is maturing within less than twelve months and which carries a margin of 195 basis points over EURIBOR (floored at 0%). This represented a decline of €7.1 million versus December 31, 2021, reflecting seasonality in some of our scheduled vendor financing payments and negatively impacting our Adjusted Free Cash Flow by the same amount in Q1 2022. For the full year 2022, we anticipate a broadly stable evolution from December 31 2021, as embedded in our FY 2022 Adjusted Free Cash Flow outlook, yet with a certain seasonality in some of our payments from quarter to quarter.
All of our floating interest rate risk and foreign exchange currency risk have been hedged until the maturity of such debt instruments through a series of derivatives, improving the visibility on our future Adjusted Free Cash Flow. Excluding short-term liabilities related to our vendor financing program, we face no debt maturities prior to March 2028 with a weighted average maturity of approximately 6.3 years at March 31, 2022. In addition, we also had full access to €555.0 million of undrawn commitments under our revolving credit facilities at March 31, 2022, with certain availabilities up to September 2026.
For more information on our debt instruments and payment schedule at March 31, 2021, we refer to the Q1 2022 Investor & Analyst Toolkit.