If you have a client or project retainer that you want to apply to the invoice while creating it, here is how you can do that in the batch invoice mode:
- Open the Billings > Invoices screen.
- Click Create New > Batch Invoice.
- Enter the necessary filters on the Invoice Filters and Options dialog before continuing.
- Click More > Show/Hide Columns and select Retainer.
- Enter the retainer amount to be applied to the invoice and process the invoice as final when done. Check the Core Help for more.