When importing a CSV for a transaction import, does anyone know how to get the CSV column to automatically map the item ID to use internal ID instead of name by default? Invoice Items : item auto maps it and the default selection is set to 'Names'

You can save the mapping, but if you are doing it for the first time, you will always have to select internal ID, Name is by default.

Thanks

Yes. Saving your import with mappings remembers your ID preference