We use Unishipper for UPS because they provide us with lower rates than Shopify's discounted UPS rates. We tried plugging our Unishipper issued UPS number directly into Shopify, but Shopify would NOT pull the correct rates (the rates were much higher than our actual Unishipper/UPS rates). Then we installed the Eniture Unishipper app. Problem solved! Now we're pulling the rates correctly and we can pass our reduced UPS rates directly to our Shopify customers. :-)
Great app. Truly excellent support!
Creative Control Products
Easy to install and provides my customers with the lowest rates possible on their shipping. Customers are always abandoning our cart due to shipping rates and Unishippers pricing has lead to more sales.