To generate invoices for all your clients/cases (projects) using all previously unbilled-time and expenses, please follow these instructions (for generating an invoice manually in two clicks for a case, see Getting Started paragraph 12 onward): 
IMPORTANT NOTE: For generating valid LEDES format invoices, for the clients that require LEDES format invoices, please ensure that you have entered data as described in the LEDES Invoice page.
You may enter standard text (e.g., Make check payable to ) in your clients' details prior to performing the following steps. 
Note: All billable and previously unbilled-time and expense entries will automatically be used in generating invoices. If you don't want to include selected time/expense entries, please edit those time/expense notes and uncheck "Billable" checkbox prior to proceeding with the following process. Don't forget to edit those time/expense entries again, this time to make them "billable" after performing this process so that those time/expense entries can be billed later on.
1. Click on "Settings/Reports" (upper right corner). 
2. Click on "Bulk Generate Invoices" in the left side panel.
3. On the right hand side window, select Client or case (Project) for which you like to generate invoices. If you like to generate invoices for all clients and all cases, simple click on "Generate Invoice" without selecting any entries in drop-down boxes. 
4. Enter Tax Rate, if any. If there are different tax rates for different clients, generate invoices by selecting invidual clients. 
5. After clicking on "Generate Invoices" button, wait for the "Success" message. Visit the "Clients" tab and then the "Invoices" tab to download/email the newly generated invoices. You may also download these invoices from the Dashboard.