A workbook Template is just that............a workbook.
Normally one opens a copy of the Template for each single sales invoice he
writes and saves the copy and writes the invoice data to a database using the
Template Wizard with Data Tracking Add-in.
If you just want a series of worksheets for invoices in one workbook, don't use
a Template.
Just copy the sheet from your downloaded Template to a new workbook and copy it
a whole bunch of times in the one workbook.
Use each copied sheet for an invoice.
Gord Dibben MS Excel MVP