Add-ons: static IPs, managed routers and other extras

Carriers bill some things on another service's invoice: a block of static IPs on a circuit, a managed router, a voicemail-to-email pack on a phone system. Recorded as separate services they look like bills that never arrive; folded into the circuit's price they lose their own contract dates and notes. An add-on is both: its own record, billed on its main service.

1. Open the main service, the circuit or phone system the extra is billed on.
2. Under Add-ons, choose Add an add-on. The form starts on the same provider, category, location and account number.
3. Give it a type (Static IPs, Managed router, or whatever fits), its own monthly cost, and any term of its own.
4. Save. The main service now shows its price with add-ons, and its bills are checked against the two together.

What changes

• The main service's bill check expects its own price plus every live add-on's price.
• The add-on is never listed as missing a bill; its bills are the main service's.
• Totals count each price once: the circuit's and the add-on's, with no double counting.
• An add-on can be moved to another main service, or made a service of its own, from Edit details.