Dealing with fractions of a penny?

Question

If my car insurance was £1200.01 per year, I could end up being charged £100 + 1/12p per month. I know that's not how it works, the extra penny is kept whole and goes on a specific month instead. What I don't know is how the month that gets the extra penny is decided. Is there a standard accounting practice for dealing with this? For example are all the "leftover" pennies worked out in advance and added to the first payment, or are they gathered up at the end making the final payment one penny more or less? I'm writing a simple accounting package as a hobby software project so if there's a generally-accepted practice for dealing with this kind of "rounding errors" I'd like to follow it. Many thanks in advance.

Answer 1

Your contract will define the exact charges in each period. I can't answer for all insurance companies, but I suspect it is in their best interest to recognize the additional 0.01£ as early as possible. Summing up all those 0.01£ from all contracts could be material.

I can't state for certain about IFRS and if it deals with the extra amount but as far as US GAAP, there are no standards dealing with the immaterial amount.