WooCommerce prices entered including VAT

Context

Somehow, you can choose to enter product prices in WooCommerce including VAT. But when it's about an international webshop, what VAT rate is that? The received wishdom seems to be, that it is the VAT rate associated with the location of the shop (Netherlands in my case):

When you enter prices including VAT, it is assumed that this is your local VAT rate or base VAT rate; the VAT rate associated with the store address

Product fields Tax status and Tax rate are the additional fields to determine the exact tax rate

Case: Prices keep changing - 2024.04

Simple: A wrong VAT base rate is applied when calculating product prices - Quite a serious problem.

I think there were some extra problems, but this problem is good enough for now.

Additional information

• The wrong base rate was 19% in stead of 21%. This only became clear when configuring WooCommerce to display prices without VAT and to use up to 8 decimals - Appearantly, there were some unlucky roundings, that obfuscated the calculations
• This webshop was primarily focused on Germany, which happens to have a 19% VAT rate
• After removing a bunch of plugins and caching, the problem stayed the same, but what became clear (might have also been the case earlier): The wrong base rate was only applied when not logged in - Basically for visitors who would receive cached versions of the site (might just be a conincedence)
• When logging in, prices were ok. When logged out, prices were again incorrect.

Brainstorming causes

• Something with cashing? Unlikely, actually
• Something with wrong rates?
• Shop location "Netherlands" is interepreted differently than expected?

See also

• Task tk883

Sources

• https://wordpress.org/support/topic/products-prices-are-changing-on-its-own/

See also

• WooCommerce prices, locations & VAT