When a business moves its phone system into Teams, the licensing gets layered on quickly and reviewed slowly. Microsoft 365 Teams Phone and calling plans are the result, and they are a textbook example of capability that attaches to more users than need it. The fix is not to avoid Teams Phone, which is often a sound consolidation, but to match it precisely to the people who actually make external calls.
This article sits under our pillar on Microsoft 365 optimization and links up into the wider program in our guide to digital workplace cost optimization, where phone consolidation often removes a separate legacy system entirely.
How Microsoft 365 Teams Phone and calling plans fit together
There are two distinct things to license. Teams Phone provides the phone system itself, turning Teams into a business phone platform. A calling plan then supplies the minutes to reach external numbers through Microsoft. The integrated phone system capability is part of E5, but external calling still needs a calling plan or a connection to your own carrier, a distinction buyers frequently miss. Confirm the current plan inclusions and options against Microsoft documentation, as of June 2026.
Where the overspend hides
Licensing users who never call out
Many people communicate entirely inside Teams, calling colleagues and joining meetings without ever dialing an outside line. Giving those users Teams Phone and a calling plan pays for a capability they do not touch. The first and largest saving is to identify who genuinely makes external calls and license only them.
The wrong calling model
Microsoft offers its own calling plans, which are simple and priced per user, but you can instead connect your existing carrier through direct routing or operator connect. At scale, and where you already hold favorable carrier rates, a carrier connection is often cheaper. Choosing the model without comparing both against real call volume is how money leaks, so the decision should rest on data, as of June 2026.
Calling plan size mismatched to usage
Calling plans come in different minute allowances. Buying a large allowance for users who make occasional calls, or a small one for heavy callers who then incur overage, both cost more than necessary. Matching the plan to actual call patterns avoids paying for unused minutes and avoids surprise overage.
How to right size Teams Phone
Start with usage. Pull call records to see who actually makes external calls and how often. Remove Teams Phone and calling plans from users who do not call out. For the remaining callers, compare Microsoft calling plans against a carrier connection using their real volume, and choose the cheaper model for your situation. Then size each calling plan to the user pattern rather than a default. Finally, review periodically, because call behavior and headcount drift, and the licenses should track them.
The consolidation upside
Done well, moving to Teams Phone can retire a separate legacy phone system and its maintenance, which is a saving beyond the per user license. That is why phone consolidation often appears in a broader rationalization program rather than as a standalone decision. For the meeting and calling overlap with other tools, see Teams Phone versus Zoom Phone cost, and for the wider tier question see when E5 is worth it. The renewal timing for all of this is covered in our Microsoft 365 renewal strategy.
Mapping the calling population
The single most useful exercise is to segment your users by how they actually communicate. Most organizations find three groups. The largest communicates entirely inside the organization, through Teams chat and meetings, and never dials an external number. A second group makes occasional external calls, perhaps to customers or suppliers a few times a week. A third makes external calling central to their role, such as sales, support and reception. Only the second and third groups need Teams Phone and a calling plan at all, and the third group is the one whose calling model and plan size most repay careful attention. Building this map from real call records, rather than from job titles, is what turns Teams Phone from a blanket cost into a targeted one.
Calling plans against carrier connection
For the users who do call externally, the central decision is how those calls are carried. Microsoft calling plans bundle minutes per user and are simple to administer, which suits smaller deployments and organizations without favorable carrier arrangements. Direct routing and operator connect instead connect Teams to your own carrier, which can be markedly cheaper at scale or where you already hold strong carrier rates, at the cost of more setup and management. There is no universal answer. The right choice falls out of comparing both models against your real call volume and your existing carrier contracts, and it should be revisited as those change, as of June 2026.
Avoiding the common traps
Two traps recur. The first is bundling Teams Phone into a wider Microsoft 365 tier decision without separating it, so the phone capability rides along to users who will never use it. Keep the phone decision distinct and driven by call data. The second is treating the calling plan allowance as a default rather than a choice, which leads to large allowances for light callers and overage charges for heavy ones. Sizing each allowance to the user pattern avoids paying for unused minutes on one side and surprise overage on the other.
Reviewing it over time
Calling behavior drifts. People change roles, teams restructure, and external calling patterns shift with the business. A Teams Phone estate that was right sized last year quietly slips out of shape, so a periodic review, ideally annual and aligned to the renewal, keeps the licenses tracking the people who use them. This is the same discipline that holds savings everywhere in Microsoft 365, applied to the phone layer specifically.
The business case beyond the license line
The strongest reason to look hard at Teams Phone is not the per user license alone, it is what consolidation can retire around it. An organization moving its calling into Teams can often decommission a separate phone system, its maintenance contract, its hardware refresh cycle and the administrative overhead of running a second platform. Those savings dwarf the license question and are frequently missed because they sit in different budgets owned by different people. Building the business case means counting all of it: the right sized Teams Phone and calling plan spend on one side, and on the other the full cost of the legacy system it replaces. Viewed that way, the decision is rarely about whether Teams Phone is cheap in isolation, it is about whether consolidating onto it removes more cost than it adds, which for many organizations it clearly does once the legacy estate is counted honestly.