Five years ago, suggesting that a business run its phones through Teams got you a raised eyebrow. Today it is frequently the first thing a customer asks about. That shift is not really about Teams getting better, although it has. It is about three separate things arriving at the same time, and the direction they point is worth understanding whether or not you end up going that way.
The 30-second version
- The analogue network closes on 31 January 2027, so every business is being moved onto internet based calling anyway.
- Microsoft 365 is already in most UK businesses, which means the platform is bought, deployed and familiar.
- The desk phone stopped being the default somewhere around the point that everyone got used to working from anywhere.
- It is not automatically cheaper, and anyone telling you it always is has not done the licence maths.
- The likely end state is Teams as the default assumption, not Teams for absolutely everything.
On this page
Three things arriving at once
Any one of these on its own would have moved the market slowly. Together they have changed the default answer in about five years.
- The PSTN switch-off. The old analogue and ISDN network closes on 31 January 2027, so every business with a traditional phone system is being moved onto internet based calling whether it wanted to or not. Once you are having that conversation anyway, the question becomes which platform rather than whether.
- Microsoft 365 is already there. Most UK businesses already pay for it, already have the accounts, already have the security and the device management. Adding calling to something already deployed is a far shorter conversation than buying a phone system.
- The desk phone became optional. Hybrid working made the handset on the desk much less central, and a generation of staff now treat a headset and a laptop as normal. The phone became an app, and the app people already had open was Teams.
None of that is a claim that Teams is technically better than a good hosted phone system. It is an observation that the path of least resistance changed, and in telecoms the path of least resistance usually wins.
What that actually changes for a business
| Then | Now |
|---|---|
| A phone system was a thing you bought | Calling is a licence you add to something you already own |
| Handsets on desks, one per person | Laptops and headsets, with handsets where they genuinely help |
| The phone system was separate from everything else | Calls sit alongside chat, meetings and files in one place |
| Moving office meant moving the phone system | Moving office means moving the people |
| Your provider sold you hardware | Your provider sells you integration, numbers and support |
That last row is the one that matters most from where we sit. When the platform is Microsoft’s, the value a telecoms provider adds is not the box. It is getting the numbers moved without a gap, connecting the things that are not people, and being the one who answers when something is wrong.
Where it will not take over
A five year prediction is only worth reading if it includes the parts that will not happen, so here are the places we do not expect Teams to become the default.
- High volume contact centres. Teams has queueing and routing, but a busy contact operation needs workforce management, proper reporting and omnichannel handling. That is a different category of product, and the billing works differently too.
- Buildings full of analogue equipment. Lifts, door entry, gates, alarms and telecare do not have Microsoft accounts. They need their own connections, and no amount of Teams adoption changes that.
- Businesses not on Microsoft 365. Obvious, but worth stating. If you run on Google Workspace or nothing in particular, the entire argument above disappears.
- Places that need real handsets. Kitchens, warehouses, shop floors, care homes and hotels need cordless phones that survive being dropped, not a laptop.
- Anywhere the network is not up to it. Voice over a poor connection is worse than no voice. This is a solvable problem, but it has to be solved first rather than discovered afterwards.
The honest bit about cost
Teams calling is regularly sold as the cheaper option and it is not reliably true. You are adding a per user licence from Microsoft, plus the calling itself, and depending on how many people genuinely need to ring external numbers that can land above the cost of a hosted seat rather than below it.
Where it does save money is in the things around the edges: no hardware refresh, no separate system to administer, no second set of logins, and one less supplier relationship. Those are real savings, they are just not the ones on the first page of the quote.
The mistake we see most
Licensing everybody. In a lot of businesses half the staff never ring an external number from a desk. Licensing them for external calling because it is simpler to buy in one block is the single most expensive decision in a Teams migration.
What the next five years probably look like
Our expectation is not that everything becomes Teams. It is that Teams becomes the default assumption, and the interesting work moves to the exceptions.
Practically, that means a business deciding on a phone system in 2031 is likely to start from why not Teams rather than why Teams, in the same way that nobody now argues about whether email should be hosted. The conversation shifts to the parts Teams does not cover: the contact centre, the equipment in the building, the sites with poor connectivity and the people who need a real handset.
If you are deciding now, the useful consequence is that you do not need to bet the whole estate on one answer. Putting the office on Teams while the lifts, the door entry and the warehouse handsets stay on connections of their own is not a compromise. It is what the end state is going to look like anyway.
Thinking about moving your phones to Teams?
Tell us what you have, how many people genuinely ring outside numbers and what equipment is in the building. We will tell you honestly whether Teams is the right answer for all of it, some of it, or none of it.