As of January 1, the base interest rate (BIR) in Bulgaria is 4.68%, the Bulgarian National Bank (BNB) announced. This is the highest since February 2002, when BNB had raised BIR to 4.54%. The BIR was 4.58% in December 2007 and 4.26% in November 2007. In the beginning of 2007 the base interest rate stood at 3.43%.