Slack vs Teams for AI agents: access, costs and approvals

In 60 seconds: start with the channel where your team already reviews exceptions. Slack fits when context lives in its conversations and you need to connect external agents through its official, generally available MCP server. Teams fits when you already administer Microsoft 365 and want to publish Copilot Studio agents or handle approvals there. Check the technical route: the specific Teams MCP remains in preview; Microsoft recommends Work IQ for new projects. In either platform, define who can approve and where the action is recorded before enabling writes.

Verdict by profile

• If sales and operations already work in Slack, test a task that needs to consult conversations and return a proposal there. Its MCP server and Real-Time Search API are generally available.
• If you already operate on Microsoft 365, test Teams with a Copilot Studio agent published to that channel. Confirm that IT allows installation and sharing with the intended users.
• If you depend on Salesforce, assess Agentforce in Slack, including its license. If you need private lookups in a shared channel, resolve answer visibility first.

These are design recommendations for B2B operations, not benchmark results. This comparison covers internal work and human review; the customer can keep talking over WhatsApp while the owner makes a decision in Slack or Teams.

Comparison at the same scope

Official sources checked on November 4, 2026. Prices are USD references from US pages, not LATAM quotes. We separate the channel from the agent and its usage charges. “Not published / verify” means a purchasing condition still needs confirmation.

Criterion	Slack	Teams
Verified entry price	Free: USD 0. Pro: USD 7.25 per user/month billed annually or USD 8.75 monthly, excluding promotions. Country-specific taxes: verify. Plans, taxes	Teams Essentials: USD 4 per user/month, paid yearly with automatic renewal. This buys the channel, not an equivalent agent. Taxes and local offer: verify. Plans
Where processing and data live	Cloud service; configurable residency for certain data at rest on Business+ and Enterprise. The agent client adds its own processing. That provider’s region, retention and copies: verify. Residency	Teams stores data according to the tenant’s region; check it in administration. Review agent and connector processing and retention separately. Location
MCP status	Official server and Real-Time Search API in GA. Assess third-party bridges separately. Announcement	Specific Teams MCP: preview, for compatibility and testing; Microsoft rules out production and new-project use. It recommends Work IQ with the GitHub Copilot harness. Work IQ is listed as GA in Copilot Studio, while individual workloads can remain in preview. Teams MCP, Work IQ
Authentication	MCP uses confidential OAuth and a user token, with per-tool scopes such as chat:write. Do not interchange that token with a bot token. MCP documentation	Copilot Studio supports Microsoft Entra ID authentication. Each tool can use a user or author connection: check the configured choice. Conversation, tools
Respects user permissions	The official MCP documents access that respects user permissions. That does not authorize posting a private result to any channel. Access model	To restrict a tool to the user’s data, select user authentication. Do not assume their sign-in limits an author’s connection. Tool access
Native and ecosystem agents	Slackbot as a personal agent, depending on plan; Agentforce is built in Salesforce and added to Slack. Slackbot, Agentforce	Copilot Studio lets you publish custom agents in Teams; sharing the agent and installing it are separate steps. Publishing
Required licenses	Agentforce requires a Salesforce Agentforce license, even on the Free channel plan. Final price for that configuration: not published / verify with sales. Also confirm the external client’s plan. Requirements	Confirm entitlements and consumption for your scenario. As a separate reference, Copilot Studio offers packs of 25,000 Copilot Credits for USD 200 per month and pay-as-you-go. This does not equal 25,000 tasks. Pricing
Integrations	MCP supports search, reading/sending messages and working with files, canvases and lists. CRM access depends on the tools you choose. Capabilities	Work IQ MCP exposes tools to read, create, update and delete Microsoft 365 entities. Review the scope of each connection. Capabilities
Approvals from the channel	Block Kit supplies buttons and menus to build the interaction. Your application must validate and execute the process. Block Kit	Approvals lets you send a card from a chat or channel. Connecting it to the agent and business system requires workflow configuration. Approvals
Limits	MCP is limited to internal apps or apps published in the Marketplace; unlisted apps are excluded. Limits apply per tool and action. MCP restrictions	In the documented Copilot Studio publishing route, knowledge sources requiring user authentication, such as SharePoint, are limited to 1:1 chats; they are unavailable in groups or channels. Rate limits also apply. Teams limits
LATAM support	Local price, billing, language, hours and SLA for your channel/agent combination: not published / verify with each provider. Plan terms	Phone and web support advertised for Essentials; language, local billing and your integration’s SLA: not published / verify. Plan terms

Microsoft’s distinction affects implementation: the cited publishing guide describes agents using the standard harness; Work IQ uses the GitHub Copilot harness. Validate compatibility across the entire route before promising a Teams experience. Microsoft documents both models.

Agent 365 is generally available as an agent governance platform. That status does not change the status of each MCP server or workload.

Decision criteria

Start with an exception that currently needs review, such as an out-of-policy discount. The agent should gather permitted context, prepare a proposal and request a decision from the owner. Use the same fictional cases in both options, including one the user is not authorized to access.

Check identity first: who invokes the agent, which connection it uses to query the CRM and who receives the answer. A document available to the requester may be private to other channel members. Post a minimal summary and put sensitive detail behind an authenticated view. In Teams, test 1:1 chat and shared channels separately, given the documented restrictions.

Then compare the full workflow cost: user and agent licenses, consumption, connectors and infrastructure, plus maintenance. Request an estimate based on your tasks and frequency; credits have no fixed equivalence to an approval. Include who will handle an expired connection or an unanswered request.

Accept the pilot when you can demonstrate that it blocks unauthorized access, preserves the decision and executes the approved version once. Record the failures you find; this guide assigns neither success rates nor savings to either platform.

Human approvals from the channel

A useful card shows the proposed action, its target record and its consequence. The button must identify a specific request. In Slack you can build it with Block Kit; in Teams you can start with Approvals in a chat or channel. You do not need MCP to present that decision.

The following pattern is an implementation recommendation:

1. Store the pending proposal in the business system with an ID, version, requester, authorized approver and expiry. Show only the necessary context in the thread.
2. When someone selects approve or reject, validate their current identity and authorization in the backend. A free-text “OK” is insufficient to execute.
3. If the amount, recipient or proposal changes, request a new approval. If the deadline expires, block the action and escalate to the designated backup; silence does not approve.
4. Execute once and store the outcome alongside the decision and its date. Retries must recognize an already processed operation. Keep “approved” and “executed” as separate states so failures can be handled.

The guide to sales approvals in Teams with Power Automate develops this workflow. To continue with the customer, see sales follow-up across WhatsApp and Teams: the internal approval should belong to the same case as the external send.

When to choose neither

If there is no discount policy yet or nobody handles exceptions, keep manual review while you define owners. Automating an ambiguous request leaves that ambiguity inside the channel.

If you cannot separate private data from shared replies, use an authenticated CRM or portal view. Also defer integration when the provider’s residency, retention or processing terms do not fit your operation, or when there is no budget to maintain it.

A task with stable rules may work with a deterministic workflow and a review queue. Add an agent when the task needs context interpretation and you can bound its actions.

Next step

Choose a sales exception, its approver and the fields they can see. Test approval, rejection, expiry and double clicks with fictional data before connecting a real write. For another architecture decision, the comparisons hub groups guides by problem type.