Accurately calculating Dimensional Weights/Cubic Ra with Shopify's USPS Rates and a Third Party App

[specklefarms]

The issue is that the Third Party App requires USPS credentials, which we sign up for at the USPS website. But these rates are 75% accurate, with the other 25% charging my customers 20% or more on shipping. I've searched and asked Shopify and the app support for the past few years for Shopify's USPS credentials, but they haven't been made available.

Does anyone have a solution to this?

[Keerthi_Sree]

Hello @specklefarms 

There are two key points to keep in mind:

1. Most third-party apps that offer USPS integration require you to have your own USPS Business Account and API credentials. Unfortunately, you won't be able to use Shopify's USPS credentials with third-party apps.
2. To use cubic or dimensional weight, product dimensions need to be configured. These dimensions aren't available by default in Shopify, so you may need to be on a higher plan to utilize metafield mapping for product dimensions.
   
   

With these considerations, I recommend trying the PH Multi Carrier Shipping Label app. It integrates with the latest USPS REST API, allows you to configure product dimensions, and supports USPS box configuration along with cubic/dimensional weight calculation. This app provides all the functionality you're looking for, plus it comes with a 14-day free trial.

Once you've received your USPS account details and API credentials, feel free to reach out to our support team, and they'd be happy to assist you.

[specklefarms]

Thanks for your response.

1. So you're saying that we're not able to get accurate USPS shipping rates.

2. We already have this handled by a third party app, but it really doesn't say whether your solution for the shipping prices generated will be an exact match to what Shopify generates when we make a shipping label when using USPS.