I have a few large heavy items that we sell that cannot go UPS or USPS so we use trucking companies for them and charge a flat rate, however even though the flat rate is displayed as an option UPS and USPS both give the option of shipping the 150+lb product for $9.95 (I’m assuming a default?)
How do I remove the UPS & USPS options from shipping these few heavy items and just have the flat rate?
You can assign a separate shipping class to these items and define a dedicated shipping rule based on Shipping class. Set a flat rule for that rule and you are done!
For your convenience, I have attached a screenshot to show you this : https://ibb.co/buMmOd
Do try this and let us know if you have any query.