Craft Commerce multisite, different tax rates In Craft 3, Commerce 2 is there a way to set a different tax category or rate on a cart/site when using commerce in a multi site environment? Site A (b2c website) has tax rate 1 (21% with tax included in price) and site B has tax rate 2 and 3 (21% with tax excluded in price and a 0% tax rate). Both sites use the same products/inventory but are targeted for different audiences (b2c and b2b).

I’m looking for a solution that works simular like posting  to the update-cart action when adding products to the cart. 

Or, even better would be to be able to set defaults for the cart when setting {% set cart = craft.commerce.carts.cart %}.
As of Commerce 2.0, there is no support for multi-site apart from a product’s custom field information.

A cart exists in the session, once per Craft installation, and there are not separate carts per site. 

Multi-site is something we plan to add in the future.

Having said that, a cart stores the current orderLanguage based on the current language of the site the order is being made in. A custom adjuster could be written to add custom tax costs based on this information: https://github.com/craftcms/commerce/blob/develop/docs/adjusters.md