IRS mileage rates can change yearly. We need to show the full rate to some clients so they know they are being billed for the current rate. Only showing 2 decimal places doesn't allow us to show the full rate.
This is an issue shows up in reports and invoicing. The expense sheet allows you to enter more than 2 decimal places. It allows you to enter $0.535, but when you pull a report or bill on an invoice it rounds it up to $0.54. This throws off the total on the invoice.