By default, invoice payments are meant to be paid separately and directly by clients. However, at any point after creating an invoice, you can offset the invoice amount by way of previously-requested trust funds in the trust account.
To add trust funds to invoices:
Head over to Invoices
2. Click the card-like icon in front of the choiced invoice
3. Select your firm’s trust account as a Payment Source
4. Choose the client’s balance as a Source
5. Select the Destination account where the payment would be received
6. Click Add Payment