Expect it, plan for it, and do not treat it as clients being careless. A number someone saved two years ago is in their phone, in their call history, on a card in a drawer, and in the muscle memory of ringing you. Announcing a new one does not delete any of that.

Two-number confusion is the failure mode of the whole separate-number approach. It is not a footnote. Some practitioners have gone through a switch, found themselves running two lines badly, and deliberately collapsed back to a single phone for their work and personal life — not because separation was a bad idea but because the half-completed version was worse than either end state. One describes exactly that: a forwarded after-hours line meant a client in crisis got a callback from a number they did not recognise, was confused by it, and the practitioner went back to one number for simplicity.

So the thing to get right is not the announcement. It is the six weeks after it.

Why it happens even when you did everything right

The old number still works. As long as it rings, some people will use it, and each successful call teaches them it is still fine.

You are still handing it out. This is the most common cause and the most embarrassing one. An intake form nobody updated, an email signature, a directory listing, a voicemail greeting on the old line that still gives the old number, a letterhead, an invoice template.

They never read the message. A single announcement in a channel someone does not check is not a notification. It is a hope.

A third party has the old number. A family doctor's office, an employee-assistance coordinator, a parent, a school. They will keep passing it on for years.

What actually makes a switch stick

Tell everyone once, in writing, with a date. Not "I'm getting a new number soon" — the new number, the date it takes over, and an instruction to save it as a contact. Saving it is the part that matters, both because it makes them dial the right one and because a saved contact shows your name rather than an unknown number when you call out.

Say it again in session. The written notice reaches the people who read notices. The people who do not read notices are the ones who will call the old number, and the only channel that reaches them is you, out loud, at the end of a session.

Keep the old number alive for a while. Do not cut it dead. The awkward case is not the client who misses the announcement; it is the one who rings the old number in a bad moment and gets nothing.

Make the old number carry the message. Change its greeting to state the new number, twice, slowly, and then say it again at the end. Where you can, forward it. A forwarded call that reaches you is a chance to say "this number is changing, save the new one" while you have the person on the phone.

Hunt down every place the old number is published. Website, directory listings, invoices, intake paperwork, consent forms, insurer records, referral partners, your own email signature. Write the list down and work through it, because the ones you miss will keep producing calls indefinitely.

Only ever give the new one out. The practical failure after a switch is rarely clients ignoring the new number. It is the practitioner still handing out the old one out of habit.

The case that does not resolve

If your old number is your personal cell, you cannot retire it. It is your number, it is how your dentist and your kid's school reach you, and it is going to keep ringing forever.

That means the plan above has no endpoint. What you can do is stop the old number being an option in any new context, keep answering the ones that come, and redirect each caller once, plainly: "This is my personal line — use the practice number, here it is again." Most people move after being told twice. A few will not, and you decide individually whether that is a boundary conversation or a thing you absorb.

When not switching is the right call

Worth saying, because the answer is not always "switch".

If your caseload is small, stable, long-standing and low-acuity, and everyone already has a number that works, the switching project may cost more than it returns. Same if you are within sight of winding down the practice. Doing nothing is a legitimate choice, and it is better than a switch you abandon halfway, because a half-switch produces exactly the confusion you were trying to end.

The one situation where switching is worth the disruption anyway: the current number is your personal one and it is now attached to your professional name publicly. That is the case where doing nothing has a cost that keeps growing.

The short version

Announce once in writing with a date, repeat it in session, keep the old number answering for a while with a greeting that says the new one, forward it if you can, and purge the old number from every place you publish it. Then check, a month later, which clients are still calling the old line and tell those people directly. It is not elegant. It is the difference between a switch that finishes and a switch that becomes a permanent second problem.

About Rivet

Rivet is a Canadian practice line built for therapists — a separate number for calls, texts and voicemail, with video sessions and clinical tools in the same place. Your data stays in Canada, and transcription runs on Rivet's own hardware rather than a third-party AI service.

One plan, $65 CAD a month, everything included. Fourteen-day trial, no card.

See what's included · Start the trial