Do Custom Shipping Rates Work? Having problems

Shopify Discussion

Topic summary

Custom shipping rates in Shopify aren’t appearing during checkout despite being configured in the general “Shipping and delivery” profile.

Key details:

  • Strategy: assign products tiny “out-of-practical-range” weights to trigger specific custom shipping options (while still allowing USPS/UPS calculated rates).
  • Locations/zones: United States and “Rest of the World.”
  • Previously worked: a 0.0–0.03 oz rule successfully surfaced “Free Shipping.”

Current issue:

  • New rules created for 0.04 oz (Free US / $12 international) and 0.05 oz ($6 US / $12 international).
  • A product was set to 0.04 oz (store default weight unit is oz), then the user refreshed/re-logged and tested checkout.
  • Result: none of the custom rates show up for either US or international checkouts.

Status: unresolved; the post asks for ideas on why the custom rates are not displaying.

Summarized with AI on February 25. AI used: gpt-5.2.
1

I’m having issues with setting up custom shipping rates. Nothing big deal, I’m working off the general profile under “Shipping and delivery”. The current interface is better than it was, but I can’t get it to work.

My strategy is to use arbitrary, out-of-practical-range custom shipping weights for certain products to force certain shipping options to appear. (Customers are always free to choose the USPS and UPS rates, but my custom one should come up first.)

My locations are United States, where I am, and Rest of the World (where I’m not =)).

This has worked in the past, I set a rule where 0.0oz-0.03oz causes “Free Shipping” to come up.

But today, I tried setting up custom weights of 0.04oz (Free for US, $12 for Int) and 0.05oz ($6 for US, $12 for Int). Then I took a product and set it to 0.04oz (careful that it’s always oz, and my default store weight is oz), refreshed and relogged in, and selected that item and checked out.

But.. my custom rates are not coming up as options, either for US or Int. Any ideas why not?