When setting up Easyship Rates in your Shopify store, there are some settings that need to be added.
Provided that you have 3rd Party Calculated Rates enabled on your Shopify store and connected your Easyship account with your store.
Video Guide
Activate Checkout on Easyship
In the Store Settings (Connect > Store) scroll to Shipping at Checkout. Click Activate.
Information regarding Active Shipping at Checkout settings can be found here.
Correct Shipping Zone/Rate Setup in Shopify
Step 1: Navigate to the Shipping Settings in Shopify. Click Manage Rates.
Step 2: Set up shipping zones. In the below example, we have domestic and international zones with no rates enabled. These zones don't include pre-existing rates, but if your zones have rates, we suggest deleting them when adding Easyship.
Proceed to click Add rate.
Step 3: Once clicked, select Use carrier or app to calculate rates. If connected, you will see Easyship (Rates provided by the app) on the dropdown list of available apps.
Select all available services and click Automatically show new shipping services to customers when they become available. This is essential in order for live checkout to work properly. You can always block rates from showing up in your Shipping Rules.
Your zone and rate are now set up! However, there are additional requirements in order for rates to be 100% accurate.
Additional Requirements
Products: Your products on Shopify must be synced to Easyship, and include all required details (weight, dimensions, product category). Learn how to set up products accurately here: Adding and Editing Products
Boxes: In order to ship products, you must use packaging for your shipment. Saving frequently used packaging is essential when it comes to accurate rates at checkout, as Easyship's box selection algorithm will assign a saved box that fits the order best. Learn how to set up boxes accurately here: Saving Shipping Boxes
Markup Shipping Costs
Note that you can also mark up prices to account for handling/processing fees by a certain percentage or a flat amount in the rate profile in the above screenshot.
To read up more on Shopify Shipping Zones, check out Shopify's Help center located here: https://help.shopify.com/en/manual/shipping/zones