USPS not an option, only UPS for shipping

New Member
4 0 0

When I add a certain combination of items, USPS disappears as an option in my store and only UPS is available.  Why would this be?  Does it have to do with the default box dimensions?  If so, what would I need to update for the correct box dimensions to be chosen when people purchase different combinations of items?  Thank you so much.  Grant

Shopify Staff
Shopify Staff
138 32 36

Hi @Maukapens,


Dani here from Shopify. Thanks for writing in!


Most likely this has to do with the weight of the order once a certain number of products have been added. It may be that USPS rates are only offered up to a certain weight threshold, and once surpassed UPS are the only rates offered.


I found on the USPS website that the maximum parcel weight is 70 lbs, but some mail classes have lower weight limits. This could be the reason why you're no longer seeing USPS options at the checkout.


Are you using any shipping apps on your store to take into account product size dimensions? Have you noticed a specific combination of products that leads to the USPS rates not appearing?


I hope this helps. Let me know if you have any further questions!


All the best,



Dani | Social Care @ Shopify
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449 1 7

The question can be better answered if you had mentioned which USPS service disappeared. If you want to get First class rates, then make sure that the total weight should not be more than 13 oz. If you are using flat rate boxes, then the weight should be less than 70 lbs. 


So now, if you are adding 2 or more products, and if the total weight is more than 70 lbs for priority services, then USPS rates would not show. This is happening because Shopify calculation is based on total weight of the order. This is definitely what majority of the customers want, hence Shopify's solution is tailored for them. However, if you are looking at specific box packaging, then using the Multi Carrier Shipping label app, you can assign boxes and based on the dimensions, automatically the products will be packed into large priority flat rate box, small or medium boxes or any other box.