How do I apply retainers while invoicing?

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:

1. Open the Billings > Invoices screen.
2. Click Create New > Batch Invoice.
3. Enter the necessary filters on the Invoice Filters and Options dialog before continuing.
4. Click More > Show/Hide Columns and select Retainer.
5. Enter the retainer amount to be applied to the invoice and process the invoice as final when done. Check CORE Help Center for details.