Can Microsoft Teams in Business Basic chat with external users?
The question
Can MS Teams as part of Microsoft Business Basic enable chatting with external users?
The answer
Hi — thanks for asking. Good news: this one already exists, so there’s nothing to build. 🙂
Short answer: yes — as long as your Business Basic plan is one of the versions that includes Teams (more on that in a second). Chatting with people outside your organisation is a standard part of Teams, not an enterprise-only extra, and it’s on by default.
In most cases you don’t need to change a single setting. Open Teams, start a new chat, and type the person’s full email address — if they’re in another Microsoft 365 organisation, it usually just connects. The feature is called external access (or federation), and the default setting is Allow all external domains.
The one thing to confirm first: Business Basic is now sold in a “with Teams” and a “without Teams” version. If you’re on the without-Teams one, you’d need Teams alongside it — Teams Essentials is about $4/user/month (USD, annual). Worth checking in the Microsoft 365 admin centre before anything else, because that’s the only situation where the answer is “no”. (Compare Teams plans · my Business Basic notes)
What external chat can and can’t do
You get 1:1 and group chat, calls, meetings, video and presence with people in other organisations. Screen sharing works too, though it’s most reliable in a 1:1 chat between two Teams work accounts.
⚠️ What it can’t do: share files, or give the other person access to your teams, channels or SharePoint sites. It’s conversation only — that catches people out, so it’s worth knowing up front.
Admin controls live at Teams admin center → Users → External access. 📄 Manage external meetings and chat
If you do need to swap files, there are two other routes — both included with Business Basic’s Teams:
- Guest access — invite someone into a team so they can see files and channel conversations. Guests don’t use one of your Microsoft 365 licences, though heavy guest usage can attract a small Microsoft Entra External ID charge above the free tier. Set up in Users → Guest access, plus matching sharing settings in Entra ID, Microsoft 365 Groups and SharePoint — it’s the fiddliest of the three, because the switches live in several places. 📄 Guest access in Teams
- Shared channels (Teams Connect) — one channel both organisations work in, using their own accounts, with no guest account created. Needs an Entra admin in both organisations to set up cross-tenant trust, so it depends on the other side’s cooperation.
If chat isn’t working, the order I’d check:
- Both sides have to say yes. Federation is two-way. If the other organisation blocks yours, or hasn’t enabled external access for that person, chat quietly fails no matter what you set on your end.
- Careful with the allow list. If you add even one domain to the allowed list, every other domain is blocked — people add a partner’s domain and accidentally cut off everyone else. To block just a few, use the blocked list instead.
- Personal Microsoft accounts are a separate toggle on the same page (on by default in commercial tenants, but not available in GCC, GCC High or DoD).
- Trial-only tenants are blocked by default — if either side is on a trial, someone has to change it.
📄 The comparison table I’d bookmark: External access vs guest access, side by side
If you tell me what you’re actually trying to do — just chat with a client, or properly collaborate on files with them — I’ll point you at the right one. 🙂
— Sush