In the Job List, you can filter jobs that are "Ready to be invoiced." From the Job Status dropdown list, you can select either Completed, Completed Not Fully Invoiced or Ready to Invoice. The logic behind this is you are invoicing for a job and can be at various levels so invoices are tracked from the job level.
Jobs can be marked as completed either by the technicians (after they completed the work on site) or by the office person who does the invoice and filter jobs accordingly (ie. Completed, Completed Not Fully Invoiced or Ready to Invoice) and generate the invoices. Invoices can be done in Bulk as well via the Bulk Actions icon.
While in theory, having an alert for a job ready to be invoiced may sound good, it’s impractical when you have hundreds of alerts in a day at various times whenever a job is ready to be invoiced. Filtering based on the status minimises distractions and is a preferred way based on clients' feedback and also ensures that Jobs don’t just slip off the alerts list and are missed..