The honest answer: not natively. Teams and Slack are competing products from competing companies. Microsoft has no incentive to build native interoperability with Slack, and Slack Connect (Slack's external collaboration feature) only works between Slack workspaces, not between Slack and Teams.

So if your company runs Teams and a partner, customer, or vendor runs Slack (or vice versa), the standard options are: ask one side to use the other's platform, fall back to email, set up a webhook relay (one-way, bot-attributed, limited), or use a native bridge. This post is about the last one.

Why email doesn't cut it

The instinct to fall back on email for Teams-to-Slack communication is understandable. Email is universal, everyone has it, it works.

The problem is speed and relationship quality. A question sent by email at 11am may get an answer at 4pm. A follow-up may arrive tomorrow. A conversation that would take ten minutes on chat takes a week on email. For time-sensitive work (sales, support, project coordination, partnership operations), that latency is genuinely costly.

Beyond speed, there's relationship quality. Chat builds familiarity in a way email doesn't. The informal texture of chat, quick reactions, casual questions, natural back-and-forth, creates working relationships that are qualitatively different from email correspondences. In long-term partnerships, customer relationships, and enterprise sales cycles, that relationship quality is a real differentiator.

How TetherChat bridges Teams and Slack

TetherChat installs as a native app in both platforms, in the Teams App Store and the Slack App Directory.

Once installed on both sides, creating a bridge takes two steps. In the Teams channel you want to connect, add TetherChat and create a new Tether. Copy the Tether ID. In the Slack channel you want to connect, install TetherChat and connect to the existing Tether using that ID.

From that point forward, messages in the Teams channel appear in the Slack channel in real time, attributed to the actual Teams user and not a bot, and messages in the Slack channel appear in Teams in real time, attributed to the actual Slack user.

Both sides experience a native conversation in their own platform.

For the Teams user: messages from Slack appear in their Teams channel with the sender's name and content. Replying works normally: they type in Teams, it appears in Slack. There's no indication that the other side is on a different platform.

For the Slack user: messages from Teams appear in their Slack channel with the sender's name and content. The channel behaves like any other Slack channel.

Both sides can use their platform's native features: mentions, reactions, file sharing, thread replies, formatting.

What people use this for

Enterprise sales: your sales team is on Slack, your prospect is on Teams. Instead of asking the prospect to install Slack or routing everything through email, bridge a shared deal channel. Fast response times signal attentiveness. The deal channel becomes a relationship channel that persists through close and into the customer relationship.

Customer support: your support team is on Slack, your customer is on Teams. Bridge a dedicated support channel so the customer reaches support in their own platform. Faster questions, better context, higher satisfaction.

Partner operations: your team is on Teams, your partner is on Slack. A bridged channel handles the day-to-day operational communication that keeps the partnership running without either side maintaining a secondary app.

Post-M&A integration: the acquired company runs Slack, the parent company runs Teams. A set of bridges for integration working groups keeps communication flowing without forcing a migration mid-integration.

TetherChat is free during beta, no credit card required. Install on both sides and create your first Teams-Slack bridge in under ten minutes.