Amortisation Table vs Account Statement

Hi,

on commencement of my Fixed Rate mortgage I was provided an Amortisation table where, for the first year I see a gradual decrease on the interest portion of a payment as follows:

658.21
656.84
655.46
654.07
652.68
651.29
649.89
648.49
647.08
645.67
644.26
642.84

However, on completion of a first year the actual account statement shows a more fluctuating up/down pattern per month:

672.12
615.02
667.83
644.95
655.01
642.21
662.17
660.79
638.13
657.92
635.34
655.05

The overall cost of interest for the year is basically the same so I assume all is well. Why would the interest charged not follow the smooth decreasing format of the amortisation table though?

Looks like the actual is based on no. of days in the month , Feb being lowest and months with 30 days being lower than those with 31 . But have no fear , whichever method the bank chooses , it won't be to your advantage even if its only a question of pennies .
pjq