Announcements in Slack and Teams: Banner Posts and Mentions
When a message needs to reach everyone and stand out, Slack and Teams take different routes. Teams ships a dedicated announcement post type with a headline bar and a colored or custom background. Slack has no announcement format at all: it relies on the @everyone, @channel and @here mentions to push notifications, with the general channel as the company-wide stage. Here is what each help page documents.
Miles Crawford
The quick version
In Teams, pick the Announcement post type in any channel, type a headline, then choose a color scheme or upload a background image so the post stands out in the feed. In Slack, write a normal message and lead with @everyone (general channel only), @channel or @here to push a notification; there is no banner styling, so the mention is the announcement.
Slack: three mentions, three audiences
Slack's announcement mechanism is mentions. @everyone notifies every person in the general channel, the one channel all members (except guests) are automatically added to, whether their availability is active or away; by default, guests cannot use it. @channel notifies all members of the channel you post in, active or away, with a desktop or mobile notification. @here reaches only the members who are actively working in that channel, which makes it the polite option for time-sensitive but low-stakes news. These mentions are available on all plans, and by default all members and sometimes guests can use them.
Slack: limits and admin controls
The mentions come with guardrails. They do not notify people whose notifications are paused, and they do not notify anyone when used in threads. In channels with at least six members, Slack asks you to confirm before the message sends, a warning owners and admins can turn off. In an Enterprise organization, channels with 10,000 members or more restrict @channel and @here to owners and admins. Owners and admins with permission can also restrict who is allowed to use @everyone, @channel and @here at all; Slack itself suggests using them sparingly and mentioning individuals directly when you only need one person's attention.
Teams: a dedicated announcement post type
Teams builds announcements into the composer as a post type, with options for dynamic backgrounds and AI-powered image generation so the post stands out. How you start one depends on your channel layout. In the posts layout with new posts at the top, go to the Posts tab, use Post in channel at the top, and select Announcement under the box where you type. With new posts at the bottom, select Post in channel at the bottom, then the Post type button next to Post, then Announcement. In the threads layout, go to the Conversation tab, use Type a message at the bottom, then select Actions and apps, then Announcement. You can flip the post order through More channel options by choosing See new posts at top or bottom.
Teams: formatting and scope
Once the announcement composer is open, you type a headline, select Color scheme to change its background color, or Upload an image to give it a custom background image. One scope rule matters: announcement messages are available only in channels, not in group or one-on-one chats, so the company-wide push always happens in a channel people already follow.
Which one for what?
Our read: Teams wins when the announcement itself needs to look important, since the headline bar and background make it visually distinct from ordinary posts without any notification tricks. Slack wins on delivery control: @here for people working now, @channel for the whole channel, @everyone for company-wide news from the general channel. In both tools, restraint is the strategy. Announcements lose their weight when every post is one.
What to be careful about
- Slack mentions stay silent in threads. They only notify from top-level channel messages, per Slack.
- Paused notifications win. Slack's @everyone, @channel and @here do not notify anyone with notifications paused.
- Six members trigger a confirmation in Slack. Owners and admins can disable that warning.
- Enterprise scale tightens Slack's rules. In channels with 10,000 or more members, only owners and admins can use @channel and @here.
- Teams announcements are channels-only. The post type is not available in group or 1:1 chats.
- Teams steps depend on layout. The posts and threads layouts put the Announcement option in different places.
Sources
Checked October 24, 2026. Features, steps and limits follow each product's own help articles. The guidance on when each shines is ours.