Jonas Construction Software (commonly branded Jonas Enterprise and Jonas Premier) is a full construction ERP, accounting, job costing, service management, dispatch, payroll, equipment, document management, and mobile field tools, aimed at contractors with 50-500+ employees and $10M+ in revenue. For mechanical/HVAC contractors that run large commercial installs alongside recurring service, Jonas is one of the few platforms that handles both sides in a single database instead of stitching a construction ERP to a separate FSM.
The accounting core covers GL, AP, AR, cash management, multi-company consolidation, and certified payroll, with deep construction reporting (WIP, retainage, committed costs, AIA billing, change-order management). Service management adds dispatch boards, preventive maintenance contracts, technician mobile, and work-order-to-invoice automation. Because everything shares one database, a commercial HVAC contractor can see true job profitability including service labor, parts, equipment usage, and overhead allocation.
Jonas is a heavy, on-premises-or-hosted enterprise platform, not a quick plug-and-play cloud tool. Implementations typically run $20,000-$30,000 with a multi-month rollout and dedicated training, and pricing starts around $199/user/month on an annual commitment. In return, established mid-market HVAC/mechanical firms get a system they can standardize on for a decade. Smaller service-only shops are better served by QuickBooks, Xero, or Knowify.