Magento for B2B Commerce, 2.2.x
Checkout Totals Sort Order

During Order Review, the total appears at the bottom of the order, with any adjustments for discounts, shipping charges, store credit, and tax. The order of each item determines the sequence of the calculations, and is set in the configuration by a number that is assigned to each item. For example, the Subtotal is the first item in the section, and is assigned a value of 10. The Grand Total appears last, and is assigned a value of 100. All of the other items in the totals section are assigned a value between those values.

To configure the checkout totals:

1. On the Admin sidebar, tap Stores. Then under Settings, choose Configuration.
2. In the panel on the left under Sales, choose Sales.
3. Expand the Checkout Totals Sort Order section.
4. If necessary, clear the Use system value checkbox. Then, do the following:
a. If the setting is for a specific store view, choose the store view where the configuration applies.
b. When prompted, tap OK to continue.
5. Change the number assigned to each item to determine its order in the Totals section..
6. When complete, tap Save Config.