Hi, @FP. Thank you for posting your question. I'm happy to look into this with you! To double check, are you using Shopify Shipping?
It's not currently possible to change the names of carrier calculated rates. That being said, I'd like to pass along your feedback on this. This is a request I've definitely seen before so the more feedback we get, the better! You can stay up to date on any changes and improvements to Shopify here. If this feature is added in the future, you will see it mentioned there.
If you tell me a bit more about why you'd like to change the rate names and what you want them changed to, I may also be able to suggest some workarounds for you.
Please let me know if you have any questions!
Erin | Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog