Daily mortgage calculation: problems - need clarity

hamster2013

I am confused,
took an HSBC mortgage and have so far in month 3 not managed to understand how they calculate the interst
i did a test for the last month without overpaying and here is the delta

Balance at begining of September - 02nd September - was £273118.26
next charge came 01st October, so 29 days later.
As per their announced interest rate of 2.69%, it should have been
2.69/365/100 * 273118.26 * 29
i.e an interest of £20.12844162739726 / day
and a total of £583.7248071945205
whereas, they charged me an interest of £603.89
where did the £20 extra come from ?!!

HappyMJ

hamster2013 wrote: »

I am confused,
took an HSBC mortgage and have so far in month 3 not managed to understand how they calculate the interst
i did a test for the last month without overpaying and here is the delta

Balance at begining of September - 02nd September - was £273118.26
next charge came 01st October, so 29 days later.
As per their announced interest rate of 2.69%, it should have been
2.69/365/100 * 273118.26 * 29
i.e an interest of £20.12844162739726 / day
and a total of £583.7248071945205
whereas, they charged me an interest of £603.89
where did the £20 extra come from ?!!

There are 30 days between the 2nd Sep and the 1st Oct. You need to include the first and last days.

hamster2013

well its either begining of working day or end of working day - same rule would apply for both start and end date
so if interest is calculated at 8am (just taking market opening time as example) , then between 8am 02nd september and 8am 01st october, there are 29 days