Company I write software for had a small subset of customers begin complaining about fractional cents when New Jersey implemented a sales tax of 6.625%. To be fair, company gains and loses on the half cents this caused were in equal measure. But I was commissioned to turn literally everything from UI to database to receipts and invoices and annual reports into thousandths instead of hundreds.

This is a fuckin dog boarding company I work for, not a bank. Because no, you can't screw your customers a half penny at a time... it's on you to fix the accounting and make it right.