Why is the online EX46 (UK Beer duty) form rounding the totals differently from Breww?

We’ve had a few reports that the online EX46 (Beer duty) form is rounding the final amount due differently from Breww. The online duty form is rounding half up to 2 decimal places, whilst Breww is rounding down to 2 decimal places.

Based on HMRC’s guidance, we believe their online form is rounding incorrectly, and Breww’s figure is correct. According to the two calculation examples in Section 7.7 of Excise duty notice 226, the final amount due should be “rounded down to the nearest penny,” i.e. rounded down to 2 decimal places:

This isn’t the first rounding issue we’ve noticed in HMRC’s online calculators (the other was the rounding in their online Small Producer Rate calculator), and previously, when we contacted them, they acknowledged and said that they would fix it.

We’ve contacted them again to clarify whether it is their guidance or their online form which is rounding incorrectly. Once they’ve confirmed, we can make any necessary changes to ensure your final figure in Breww matches the final figure calculated by HMRC.