Xero rounding differences

tl;dr xero has an issue with their old invoice edit page, which changes value discounts to percentage discounts rounded to 2 decimal places in order to display them this can result in rounding errors as it tries to force a value discount into its old display to resolve the issue, simply switch to their new style invoicing page explanation xero accepts invoices from breww with either a discount percentage or a discount value however, xero's old invoice edit page doesn't accept value discounts it only accepts percentage discounts to 2 decimal places this means that when trying to display an invoice with value discounts on its edit page, xero converts it into a 2d p percentage discount, which can result in rounding errors example take this breww invoice screenshot 2022 04 08 at 11 08 42|690x109 it has a £10 discount on a unit price of £148, resulting in a total value of (£148 £10) x 2 = £276 all of these details are uploaded to xero, including that the discount is a value discount at £10 per product however, xero's old invoice edit page doesn't support value discounts so if you go to update that invoice in xero, it will populate the discount field with £10 / £148 = 6 7567%, rounded to 6 76% a 6 76% discount on the pre discount value of £296 is £296 x (1 0 0676) = £275 99 screenshot 2022 04 08 at 11 11 15|690x254 this is all happening in the display xero hasn't actually saved the new rounded details until you click update or save, whereupon it will override the discount to the rounded percentage discount it has calculated if you haven't saved those new details, you can simply click "switch to new invoicing" screenshot 2022 04 08 at 11 10 08|690x295 xero's new invoicing edit page can handle value discounts in the display, you will see the correct values calculated using a discount value, not a rounded discount percentage screenshot 2022 04 08 at 11 11 59|690x288