Line level ship to addresses allow calculation of tax to be different for each line. For instance, 1 line could be going to California and the other could be going to Florida. This would make the tax rate different for each line. This can be enabled in both NetSuite and NetSuite OneWorld by turning on the "Multiple Shipping Routes" feature.
- Setup> Company> Enable Features
- Navigate to the Transactions tab
- Enable the feature Multiple Shipping Routes