Setup > Accounting > Invoicing Preferences
You can use the following options (for more information, review SuiteAnswers article (9189): Global Invoicing Preferences):
- Combine Time Items on Invoices
- Combine Billable Items on Invoices
- Combine Expense Items on Invoices
All of the above listed items will be grouped on an invoice by the custom field with Group on Invoices checkbox turned on.
Grouping takes into account the different values in the line items' columns; if some of the values is different from the other values in the grouped lines, this line is printed as separate line.