Genie has a maximum of 14 items per voucher in the ECLIPSE invoicing window. However, this doesn't mean that you can't add more items to the invoice. To add more items you will simply need to add an additional voucher by selecting Save after you have added your first 14 items. You will then be presented with a window named Step 2: Create the Voucher. Select the blue plus icon and you will receive a new voucher window where you can additional items as normal.