You may notice on many of our carrier integrations there is a default/minimum weight options available in the advanced settings. This is not available as part of our Royal Mail integration upon request from Royal Mail. This is to ensure accuracy in billing by Royal Mail.
While you can not directly add a default catch-all weight in your Royal Mail settings like you can for some other carriers, there are several other ways to handle this, depending on your workflow.
Ways to handle weights when creating Royal Mail labels in Shiptheory:
3. Edit products and add weights directly in Shiptheory.
4. Update or add product weights via the Shiptheory API.
If you would like to talk through these options to see which works best for your workflow, please contact support, we'd be happy to help.