SeriesTrack - Professional Invoice Number Management SeriesTrack is the essential tool for freelancers, small businesses, and professionals who need to manage invoice numbers with confidence and precision. KEY FEATURES: Multiple Series Management Create unlimited invoice series for different clients, projects, or business units. Each series operates independently with its own numbering sequence. Customizable Numbering Set custom prefixes (INV-, BILL-, PO-, etc.) Choose your starting number Increment or decrement with a single tap Numbers formatted with leading zeros for consistency