Bug in price calculation due to Shopify's "Dynamic Inclusive Pricing" updates(!)

[Jacco-V]

Important

We've had several of our clients (i.e. Shopify merchants that we help out as a Shopify partner) calling us because their online stores show the wrong product prices, in their non-primary market. Somewhere in the last 32 hours, Shopify rolled out an update, that contains a bug with how prices are calculated for EU countries, that are not the merchants home country.

How it used to be (correct)

price_in_other_EU_country = (price_with_VAT_in_primary_market / (1 + VAT_rate_in_primary_market)) * (1 + VAT_rate_in_other_EU_country)

How it is now (wrong)

price_in_other_EU_country = price_with_VAT_in_primary_market * (1 + VAT_rate_in_other_EU_country)

So, in effect, shoppers from other EU countries see prices with VAT applied twice, thereby raising the prices displayed by an average of 21%. I don't think I have to explain to anyone that this impacts sales a lot!

'Funnily' enough the prices correct themselves (i.e. jump back to the correct price, with an alert dialog informing the shopper that prices changed) when the shopper reaches checkout. We (and several of our merchants) have raised this issue with Shopify support, but right now (more than a day later) they have still not resolved the issue, and do not seem to see this as a priority issue(!)

Also note: we can also reproduce this issue with a fresh install of the Dawn theme.

If anyone from Shopify reads this, please escalate this issue!

[Jacco-V · Accepted solution]

This issue has been fixed.