Invoice numbering Step 1 (start number; increment number): 1. Click on the "Layout" tab. This will open the "Invoice layout" dialog. 2. Select a starting invoice number in the "Starting invoice #" field (default starting number is 100). 3. Select an increment number (the number by which each succeeding invoice number will increase) in the "Increment invoice # by" field (default increment number is 1). 4. Click on "Save." Step 2 (optional; invoice prefix): You can create a separate invoice prefix for each of your clients. (For example, invoices for "Smith Co." could be assigned "S" as its invoice prefix, and its invoices would be numbered as "S100," "S101," etc.; "Jones, Inc." could be assigned "J" as its invoice prefix, and its invoices would be numbered as "J100," "J101," etc.) Invoices for clients who are not assigned invoice prefixes would be numbered according to the starting number + increment value per Step 1 above, in the order that the invoices were created. (Thus the first invoice, sent to "Brown & Co.," would be numbered 100; the second invoice, sent to "Database Ltd.," would be numbered 101, etc.) To create an invoice prefix for one or more of your clients: 1. Click on the "Account" tab. 2. Select "Client" from the "Create..." drop-down menu (or for an existing client, click on the "Clients" link, and then on the name of the relevant client). 3. After saving the new client information (or after selecting an existing client), click on the "Billing information" link. 4. Enter a prefix in the "Invoice prefix" field in the "Edit billing information" dialog. (The prefix can be from 1 to 10 characters in length, and be any combination of letters and numbers; please avoid using special characters such as "&," "@," etc.) 5. Click on "Save."