Shiptheory Support

This error may occur when parcel and letter dimensions are entered as decimal numbers, as Whistl only supports whole numbers for their service.

Example:

In the Shiptheory settings, a package size labeled 'Large Letter' would fail due to the use of decimal places, while a size like 'New Large Letter' would work correctly because it uses whole numbers.

You can edit your custom packages sizes here: https://helm.shiptheory.com/company/package_sizes

Your default Whistl package sizes can be changed in your Whistl carrier settings.