USPS First-Class / Priority-Mail: choose cheapest rate based on weight

Learn to optimize shipping rates for USPS First-Class and Priority Mail based on weight? Learn to set up shipping rules using Liquid code on our documentation.
Are you sending with USPS and want to choose First-Class when appropriate and Priority-Mail otherwise? We got you covered. Follow the steps to set this up.
In your Rich Returns dashboard navigate to Return-Settings / General / find the section below.
Click on Configure and add all the necessary information regarding platform and API keys. We have walkthroughs for ShipStation available here and for Shippo available here.
If you are using Shippo: select the rate "First-Class or Priority (based on weight)".
If you are using ShipStation: simply select Priority-Mail as the rate and we handle the logic of using the cheaper First-Class rate if available.
In both cases the result is the same. If the weight limit allows for First-Class (1lb / 15.999 oz) then we choose First-Class, if not we choose Priority-Mail.

How is total weight calculated?

Total Weight = Empty box weight + Weight of all items in the return
  • Empty box weight: the weight you set in this very same dialog further down so make sure to double check the value you have set.
  • Item weight: the weight you have set for the variant in your Shopify store.

Does changing the weight for a variant in Shopify change the weight on existing orders?

No, orders in Shopify are immutible and therefore the weight for line-items in existing orders is not updated. Changes to the weight of a variant is available to all new orders.

Can I bulk update the weight of products?

Yes, go to the Products page in your Shopify store and use the Bulk-Edit feature to change weights for multiple products at once. Copy & Paste also works in the table-like editor.