Did you know you can create invoices in Xero directly from Google Sheets using G-Accon?
It can be done in five easy steps:
1. Prepare invoice data and select the rows you need to import
2. Invoke Upload wizard
3. Map your table columns to Xero invoice attributes
4. Check Invoice import results
5. Check invoice in Xero
More information can be found at http://www.accon.services/upload-invoices.html