Is bankers rounding officially required anywhere?

Question

I've been reading up on rounding methods and I've seen a lot of references to the "banker's rounding," but I haven't seen any financial websites that refer to it -- mostly just programming websites. I've read that the IEEE standards association requires it in some circumstances but do any accounting standards or regulations require it?

Answer 1

Banker's rounding is neither a statutory or regulatory requirement. Indeed, bankers do not care at all. There is no evidence "banker's rounding" originated in or was consistently used in banking.

Until a few decades ago, rounding calculations in the United States were performed by hand by tellers. It is probable that they used whatever rounding rule they were taught in primary school, unless they used a table or a slide rule.

Banker's rounding is a concern for programmers and because IEEE has a pronouncement on it, the safe harbor design method would be to follow IEEE and if faced with a lawsuit, the courts would generally defer to a standard.