Cutover is the day your numbers move from your old provider to the new system. It is a scheduled change at the carrier, not something anyone flicks a switch on, which is why it has a window rather than a moment.

Before the day

  • Your new system is already built, tested and running — only the numbers are still to move
  • Handsets are on desks and registered
  • We have confirmed the port date with you in writing

On the day

  1. The port completes inside its window, usually during the morning.
  2. For a short period, calls may arrive on either the old or the new system. This is normal.
  3. We test every ported number from an outside line and confirm it lands where it should.
  4. We check outbound caller ID on each extension — this is the thing most often wrong on day one.

What to do if a call is missed

Call us straight away rather than waiting to see if it settles. During a cutover we can see exactly where a call went, and a report while it is fresh is far easier to act on than one the next day.

For the first week

We leave the old service connected. It costs a little more for a month and it means there is always somewhere for a stray call to land while the change propagates.

Last checked 15 September 2026. If these steps no longer match what you see, tell us and we will fix the article.

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