Promotions and taxes restricted by shipping methods don't work for Whitelabel Sellers. They won't be applied in the simulation request (used for the cart and checkout) because the marketplace request doesn't specify the selectedSla, and so their values won't be presented to the user.

But the order creation process will send this selectedSla, where the promotion/tax will be calculated and the values will change. But the divergence between the simulation and the order creation process can block the purchase from being finished since the customer will pay a value, calculated on the simulation request, different than the value calculated on the order creation.

• create a tax in the Whitelabel Seller that is restricted to some shipping method
• create a cart in the marketplace that will use this seller, and select the shipping method specified before

The value won't be presented and the order can't be created.

There's no known workaround to have a tax or promotion restricted by shipping method in a Whitelabel seller.