Why aren't my shipping methods showing up on my site at Checkout?

If you are experiencing issues with your shipping methods not working in your site, here are some common causes:

1. No "Ship From" Location: Make sure you have a Location set up for your facility in Preferences > Locations.

2. No weight in your pricing engine: Weight of some kind must be present within your pricing engine in order for an integrated Carrier Shipping Method to successfully pull a price. If there is no weight, the method cannot work, thus will not be available at checkout.

3. Courier Info Incomplete/Incorrect. If the Shipping Method is using an integrated Carrier (UPS/FedEx/USPS), in Preferences > Settings > Shipping > Carrier Accounts, make sure the Carrier's account info is complete and accurate.

4. Shipping Method Min/Max Weights Incorrect. In Preferences > Settings > Shipping > Shipping Methods, check the Maximum Weight setting for the Shipping Method. Make sure the Maximum Weight is not set to zero. Make sure the Maximum Weight supports the weight the storefront's calculator is creating based on the item and quantity selected.

5. Shipping Method "Packaging" is incorrectly set to "Box" for UPS Ground. 

6. The cart may be too heavy. The total weight of the number of items in the cart may exceed the maximum weight for the available shipping method(s).

7. Shipping Method is not Enabled. Make sure the desired Shipping Method is turned on for the Site, under Site Name > Settings > Shipping tab. The box must be checked in order for the desired Shipping Method to be available in that storefront.

8. Permission for Site groups. Make sure the Site groups have permission in order for the shipping method to be available for the Site users at checkout, under Admin > Site (site name) > Shipping Tab > Edit shipping method and check the check box for preferred Site groups.

9. This can also happen if the shipping service provider does not provide services to that specific area, for example FedEx Ground or UPS Ground will not be available for shipping goods from USA to CANADA because for that they have International Ground Services. So if your shipping method is using Ground Services instead of International Ground Services then the Shipping will not work for the addresses in Canada because that service is not available for shipping in Canada.

10. Digitally Deliver File is enabled. The product is using an eDocBuilder template and the "Digitally Deliver File" checkbox (under Site Name < Catalog < Products < edit Product < General tab < Checkout section) has been marked. Either uncheck the "Digitally Deliver File" option, or, add / enable a non-integrated Shipping Method with 0 set as minimum and maximum weights. Items that are marked as digitally-delivered instead of printed and shipped will be assumed to have a weight of 0, regardless of what weight is assigned within the pricing engine. If a Shipping Method has a minimum weight of more than 0, it will not be triggered for these products.
One method you can use to help you determine which of the options noted above would be most helpful towards resolving the issue would be to test the shipping methods that are available on the site.  Gather the details of the items that are in the customer's cart such as the shipping address and the total weight of the items that are included.
Once you have that information, go to SiteName > Settings > Shipping tab and at the bottom of this page you will see a section called "Test Shipping Options".  Add the details from your customer's cart into the fields and click "Test Now".  On the right, the available shipping methods will be displayed and if there are any errors with the shipping methods - these will display in red as well as provide a brief description as to why this shipping method is not available.  This message will usually correspond with one of the items noted above so that the appropriate changes can be made.