Hi @bradleysp
If you’re importing a list of invoices from a CSV, then unfortunately this is restricted to just 1 line at this moment in time.
You may wish to explore our API however which would allow you to add multi-line invoices. Plus, there’s a possibility of automating the process to save you time too:
https://api.quickfile.co.uk/d/v1_2/Invoice_Create
Another thing you may wish to look at is Zapier. I don’t have access to WooCommerce to look into it in too much detail, but you may be able to trigger a new invoice through Zapier:
https://zapier.com/sign-up/?next=/app/editor/template/6901
Lastly, there is an active feature request for multi-line invoice importing that you may wish to add your vote/comments to: