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by Cshelton 997 days ago
Exactly. I think many people start overthinking things in banking. Most accounting/finance departments are ok with rounding pennies every month.

I run a Commercial Real Estate Servicing platform, where we are accruing interest on large balances daily. Our method is to not do the rounding daily, but add up all the numbers for a given period, say a month, and then round to the penny and create a single adjustment rounding transaction along with it. Accounting departments love us for it.

If we rounded daily before storing the amount, the adjustment for accounting is usually a few pennies at least every month they have to make. Our method, it's roughly $0.01 per year with monthly periods, adjusted usually at the very end. Which on a $20MM loan, is very well within the bounds of acceptable.

3 comments

I love how small details, like rounding always up for 2.50 would be significantly skewing the numbers to the higher values, so there are functions like ROUND_HALF_EVEN that would round up on even numbers, and down on uneven ones.
Yeah. I worked on a lending platform that used floats (!!!), and their response when I brought this up was that as long as the result is within something like $10, it was not an issue.

I brought up specific math problems that floats couldn't handle and they weren't phased

The real reason is because Cathrine Zeta Jones and James Bond actually did implement a program in Malaysia that collects all those rounding errors on a seperate bank account. And since it wenr global, affecting everypne, everyone thinks it ia simply normal.

Or it is because rounding errors happen and accounting is a bitch. The first option makes for a better movie plot so.

I guess I’m old because I credit that plot to Superman III. TIL it’s called Salami Slicing https://en.wikipedia.org/wiki/Salami_slicing_tactics#
Man, you and I remember Office Space differently! /s