Business Line → Personal Cell

Publish the business number. Let the PBX decide when the personal cell rings. Keep the personal number behind the switchboard.

INBOUND ROUTE

CALLER → BUSINESS DID → SIP TRUNK → PBX
PBX → OFFICE HOURS → RING GROUP 200
                     → PERSONAL CELL
                     → BUSINESS VOICEMAIL

TWO BILLABLE LEGS

The inbound call and the forwarded outbound call are separate legs. Confirm pricing, concurrent-call limits, caller-ID presentation, and the provider's forwarding policy.

KEEP VOICEMAIL AUTHORITATIVE

A cell mailbox can answer first and steal the call. Make the PBX timeout shorter, require a keypress to accept forwarded calls, or disable personal voicemail for the forwarding window.

CALL BACK THROUGH THE PBX

Calling directly from the cell exposes the personal number. Return the call through a registered softphone, a PBX callback route, or a provider-verified business caller ID.

OFFICE-HOURS SWITCH

OPEN:   DESK + CELL → ACCEPT PROMPT → BUSINESS VM
CLOSED: BUSINESS GREETING → BUSINESS VM
VIP:    EXPLICIT ALLOWLIST → ON-CALL ROUTE

EMERGENCY-SERVICE BOUNDARY

Do not imply that the PBX provides emergency calling. If a trunk supports it, register the correct service address, test only through the provider's approved procedure, and keep an ordinary mobile path available.

The public number is a boundary, not a costume.