This is more a mathematical question, but a customer is claiming QB is figuring the FC wrong.
How can I double check these? I am usually pretty good at math but must be missing something. I am guessing it has something to do with the day I assess the charge but I don't know.
Net 10, 1.5%, 31 grace period, invoice/billed date
EXP. 1)
3/15 - $577.50, 3/18 - $4286.84
Finance Charge assessed 4/28 for $99.21

I can not figure how they came up with $99.21 to prove to my customer this is correct. Please Advise

I would guess that the charge is computed on the daily balance, not just new charges. Not enough info. Regardless, this is a question for the bank.

It seems that interest charges are billed from the purchase date, not starting with net 10 days. And the rate is 1.5% per month (i.e. 18% per year).

$577.50 x 18%/yr x 44 days/365 days/yr = $12.53
$4286.84 x 18%/yr x 34 days/365 days/yr = $86.68
Total = $99.21