In Q1 2019, we carried a total debt balance (including accrued interest) of €5,877.6 million, of which €1,968.2 million principal amount is related to the Senior Secured Fixed Rate Notes with maturities ranging from July 2027 through March 2028 and €2,784.2 million principal amount is owed under our 2018 Amended Senior Credit Facility with maturities ranging from August 2026 through December 2027. Our total debt balance at March 31, 2019 also included a principal amount of €399.2 million related to our vendor financing program, substantially all of which is maturing within less than twelve months, and €23.8 million for the outstanding portion of the 2G and 3G mobile spectrum licenses. The remainder primarily represents capital lease obligations associated with the Interkabel Acquisition and the application of the IFRS 16 lease accounting standard as of January 1, 2019.
In Q1 2019, our debt maturity profile remained unchanged as compared to December 31, 2018. Excluding short-term liabilities related to our vendor financing program, we face no debt maturities prior to August 2026 with a weighted average maturity of 8.2 years at March 31, 2019. In addition, we also had full access to €445.0 million of undrawn commitments under our revolving credit facilities at March 31, 2019, with certain availabilities up to June 2023.