Shiptheory will, by default, will ignore apply any discounts that we receive as part of your orders to the order value. For example if you have a £100 order and a 10% discount code is used, we'll use £100 as the value when booking in with carriers.
However, if you'd like us to apply these discounts to your orders you'll need to enable an option that's found within your Magento 2 advanced settings. This setting will take the discounts from your orders and apply them before we book the shipment in with the carrier.
For example an order, if we take the initial example I gave above and assume there are two products within that order so it looks like the below;
Black Shirt - £50
White Shirt - £50
If we ignore the 10% discount code then we'll get an order that totals up to £100, however if you would like the discount to apply to the shipment, the option within Shiptheory will change the above order so that the product values total to £90.
With our discounts option enabled, the order above will process with the below discounted prices;
Black Shirt - (£50 - 10%) £45
White Shirt - (£50 - 10%) £45
This correctly totals up to £90 which includes the discount from the order.
If you have any questions about how this works, please contact support