Keeping the number customers already know is often the least disruptive way to add a call path. But forwarding a missed call into a receptionist—and then transferring it back to the same number—needs an explicit loop check.
Draw both directions of the call
Write the public number, carrier, forwarding condition, AfterTone destination, human escalation destination, and voicemail fallback. Trace an unanswered call and a busy call separately; carriers and phone systems may apply different settings. Do not assume a transfer destination is independent just because the labels differ.
Use a distinct reachable human endpoint
If the escalation phone itself forwards on no answer to the original public number, the route may return to the start. Confirm the actual destination and behavior with the customer's carrier and team. The specific forwarding codes and availability vary by provider, so follow that carrier's instructions rather than publishing universal dial codes.
Test beyond the happy path
With the customer's approval, call the public number during normal hours, after hours, while it is busy, and while the human recipient does not answer. Verify whether the call reaches Nova only for the agreed conditions, whether a human handoff succeeds, and what a caller hears after a failed attempt.
Keep a rollback that the owner understands
Record the prior carrier settings and who can restore them. If a route loops, disconnects, or makes voicemail unreachable, disable or revert the agreed forwarding configuration before accepting customer traffic. Log the issue and retest once corrected.
Avoid promising the path before it is tested
Twilio documents how an active call can dial another party and how to continue after an unanswered or busy attempt; that does not guarantee a particular carrier's forwarding behavior. AfterTone configures and tests number-preserving conditional forwarding with each customer, including the safe fallback, before production activation.