There is a new way to show free shipping on your products using the free_shipping_threshold attribute. This article guides when and how to use free shipping thresholds, their formatting guidelines, and best practices for e-commerce businesses.
When To Use It?
If you offer free shipping at the product level based on a minimum order value, for example, if you offer free shipping over $100, Google will show Free Shipping on your ad.
Remember
Feed level values will overwrite any Google Merchant Center level settings. This means if you have shipping rules that say Free Shipping over $150.
But for the product for which you have the attribute free_shipping_threshold, $100 will be the minimum order value for Free Shipping to show on your ads.
Also remember that, as of this writing, there will be no threshold information on your ads, which means free shipping will only be shown if you are eligible.
How To Submit The Attribute
When submitting the free_shipping_threshold and assuming the minimum order price is $100, you would add US:100.00 USD when using a text comma delimited file.
You can repeat the attribute for other countries. For example, add another column and add CA:85 CAD.
Other Methods
You can also submit free shipping by adding the attribute shipping, with a value of 0.00 USD.
Using the shipping settings within your Google Merchant Center account is also a way to show free shipping.