Note: If your orders are not syncing between your WooCommerce store and Shippo, please first disable any new plugins you may have enabled. We have seen several cases where an improperly-configured plugin caused syncing issues with Shippo. Unfortunately, there is nothing we can do in these cases other than recommend disabling that plugin.
1. Verify that the store URL is the base URL of the store. It should not have added paths like /admin, be misspelled, etc. Confirm you are entering the appropriate http vs. https for your site.
2. Your site must be live to properly connect.
3. Latest version of the WooCommerce plugin is required. It must be version 2.6 or higher to work with Shippo.
4. Verify your credentials. Occasionally wrong credentials will be accepted by the setup screen, but the order sync will not work. No error will be shown.
5a. Check that the role of the account used to connect with Shippo has the role "Administrator"
5b. Check that the permissions for the account used to connect with Shippo have the "Read/Write" permission
6. If you are getting 404 or 403 errors, these errors typically mean there is a problem with permissions or routing. If you're getting 404 errors, please check your .htaccess file to make sure you can access your WooCommerce installation at the URL you provided to Shippo. If you're getting 403 errors, please check the permissions of the files on your server to make sure they can be accessed via the web.
7. Enable REST API in your WooCommerce plugin. Within your Wordpress admin, go to the WooCommerce section, click Settings, go to the API tab and make sure "Enable the REST API" is checked. If you don't have an API tab, you need to upgrade your WooCommerce plugin - Shippo works with version 2.6 and higher.
8. Check your REST API settings by visiting the version end-point by adding /wp-json/wc/v1 to your store URL (this path depends on your store configuration). In the page header of your response, you need to check HTTP response and Content-Type. You should receive a HTTP response 200 and Content-Type application/json.
Below is an example using “curl” to get the page header of the version end-point.
"$> curl -I http://mystore/wp-json/wc/v1
HTTP/1.1 200 OK
Date: Tue, 04 Apr 2017 16:52:17 GMT
Content-Type: application/json; charset=UTF-8"
9. Verify your "permalinks" in Wordpress are set up correctly. Go to your Wordpress settings, click Permalinks, and make sure it's set to "Post Name." You can only use Shippo if your permalinks are set to "Post Name."