Porting your numbers without switching the phone system off for a minute

“Do we keep our numbers?” is the first question asked in almost every meeting we have, and it hides a better one: “how long will we be unreachable?” The answer to the first is yes. The answer to the second depends on four decisions taken three weeks before the switchover.

What porting actually is, technically

A number does not belong to a carrier: it is allocated to the subscriber and hosted by a carrier. Porting it means changing, in the country’s carrier routing databases, which operator is named as the recipient. The operation is regulated, it has statutory lead times, and it happens at an agreed date and time.

What that means in practice: there is a window, usually from a few minutes to a few hours, during which the routing propagates. It is not a switch. That window is something to place, not something to avoid.

The four decisions

1. The date, and above all the hour. Porting happens outside business hours, and the day is chosen around your activity, not around the project plan. For a medical practice, Saturday morning is the worst possible slot; for a restaurant, it is Tuesday evening. We always ask what the worst slot is, and take the opposite.
2. Keeping the old system alive through the switchover. It stays powered up and reachable. If anything is wrong, we point back and it is eight in the evening. Switching the old system off on the day is the most common mistake, and the only irreversible one.
3. The batch. You do not port three hundred numbers on the same night. You port the main number and two or three test DDIs, check for twenty-four hours, then port the rest. One DDI that does not ring gets fixed; three hundred DDIs that do not ring get endured.
4. Temporary dual routing. During the window, calls may arrive by the old path or the new one. Konvoice accepts both and sends them to the same place. Nobody on the calling side sees a difference.

A successful switchover is not the one where everything went fast. It is the one where, at no point, it was impossible to go back.

What can go wrong

• An incomplete porting authority. The subscriber name on the invoice does not match the registered company name exactly — a change of legal form that was never passed on. It is the number-one cause of rejection, and it is detectable three weeks ahead, not the night before.
• A number attached to a service everybody had forgotten. An alarm, a lift, a card terminal, an automatic gate. Those numbers sit on analogue lines whose purpose nobody remembers. The survey finds them; the switchover merely reveals them.
• An incomplete DDI range. You port 01 XX XX 00 to 99 and it turns out 47 was cancelled six years ago. The range is rejected as a block.
• A contractual notice period. The current contract has a minimum term, and porting does not cancel it. Porting is a right, but it can carry termination charges that are better costed in advance.

The real timeline

For a fifty-extension company with a main number and a DDI range, the schedule we usually hold to:

1. Week 0 — survey of what exists. Two hours with your team, and the list of numbers, extensions, queues and opening hours.
2. Week 1 — Konvoice is stood up alongside. Nobody is switched over. Test handsets are provisioned.
3. Week 2 — a pilot site or department goes into real production, on new numbers. Everybody else carries on as before.
4. Week 3 — porting authorities are filed. This is where the delay we do not control begins.
5. Week 5 or 6 — the main number and the test DDIs switch over, outside business hours. Verified the following morning.
6. Week 6 or 7 — the remaining DDIs. The old system is powered off a week later, not the same evening.

Two to six weeks, then, three of which are administrative delay. When a supplier announces a complete migration in ten days, they are counting from the moment porting is accepted; it is an honest way to count that answers a different question from yours.

See the full migration path