Slack Pro Guest Options

2025-07-15 16:13 UTC o3 Open in ChatGPT ↗

Yes — you’ve got a couple of ways to loop outside collaborators in without adding paid seats to your Pro-plan workspace:

1. Turn them into single-channel guests

On any paid plan (Pro, Business +, Enterprise), single-channel guests cost nothing.
You can invite up to 5 free guests for every paid member you already have. So if your core team has 8 paid seats, you can host 40 free guests. citeturn0search5turn0search2
Guests can see and post in one channel only, so create a dedicated project channel (e.g. #proj-partners) and add them there.
The moment you add a guest to a second channel or convert them to a multi-channel guest, Slack treats them like a normal paid seat and bills you prorata. citeturn0search5

How to set it up
Invite people → Add collaborators → Choose “Single-channel guest” → Pick the channel → Send invite.

2. Use Slack Connect (no seats added to your bill)

Instead of bringing people into your workspace, you share a channel with their workspace. They stay in (and pay for) their own org; you don’t pay for them. citeturn0search9
Caveat: Everyone’s workspace must be on a paid plan for Slack Connect channels to stay active. Free-plan orgs can only participate in one-to-one Connect DMs, not channels. citeturn0search4
If the partner org is still on Free, you can send them a Slack Connect invite — they’ll get a 30-day trial of Pro features so you can work together without immediate cost. citeturn0search1

3. Spin up a separate free workspace for the project (fallback)

If you’ll exceed your guest limit or need the collaborators to roam across multiple channels, you could create a brand-new workspace on the Free plan just for this project. That keeps your main Pro workspace lean and costs $0, but you give up Pro perks (unlimited history, group huddles, custom retention, etc.).

Quick decision guide

Need	Best option	Cost to you
≤ 5× (paid users) outsiders who only need one channel	Single-channel guests	Free
External partners already on a paid Slack plan; you want a full-featured shared channel	Slack Connect channel	Free for you
Partners on Free plan and it’s a small group that’s okay with DMs	Slack Connect multi-party DM (<10 people)	Free
Large or multi-channel collaboration and none of the above works	Separate Free workspace	Free

Tip: Whichever route you pick, document it in your Slack admin dashboard so new owners know why certain users are guests vs. Connect vs. in a side workspace.

Let me know roughly how many collaborators you have and how many channels they’d need access to, and I can suggest which path will be the smoothest.

Below is a side-by-side look at the two approaches, tuned to a small (< 10-person) Pro workspace like yours.

What you care about	Keep it in your Pro workspace and add single-channel guests	Spin up a separate Free workspace
Cost	Still $0 for the outside collaborators (single-channel guests are free and you can invite 5 × your paid seats, so ≤ 50 guests if you have 10 members). citeturn1search0	$0 for everyone (it’s a Free plan), but your core team already pays for Pro in the main workspace, so this is “additional admin overhead” rather than real savings.
Features the outsiders get	They enjoy all the Pro perks inside that one channel: unlimited apps, group huddles, canvases, lists, AI summaries, no 90-day history cap, etc. (Guests inherit the host workspace’s feature set.) citeturn1search2	They’re limited to Free-plan features: 90-day message/file history, max 3 apps, 1:1 huddles only, no shared channels, older messages auto-deleted after a year. citeturn0search0turn0search1
Experience for your own team	Everything lives in one workspace, so internal folks don’t have to switch contexts, duplicate app integrations, or wonder “Which Slack is that file in?”	Your staff will juggle two workspaces. Search, notifications, automations, and app webhooks need separate setups.
Security / governance	Fine-grained. Guests can only see that channel, while your staff keeps access to everything else. Admin controls (guest lists, retention, legal-hold, DLP, etc.) stay under the same org.	The new workspace is isolated: great if you need a hard data wall, but you now have two admin surfaces to secure, back-up, and off-board.
Channel count you need for the outsiders	Guests are capped at one channel. If the project really needs multiple parallel channels (#design-review, #qa-bugs, etc.), you either exceed the guest role or add paid seats.	Free workspace can have unlimited public/private channels, so outsiders can roam around as much as you allow.
Future-proofing	When the project wraps, deactivate the guest accounts and keep your project history intact alongside your main archives.	You can archive or delete the whole workspace when the project ends—simple but all internal records for that project sit outside your main knowledge base.

When the guest route wins

Lightweight engagement – collaborators just need a single hub (#proj-partners) for questions, file drops, and stand-ups.
You already rely on paid-plan features (more than 3 apps, group huddles, AI summaries) that the Free workspace would strip away.
Audit/compliance – you want the project’s discussion captured under the same retention policies as the rest of the company.

When the separate Free workspace makes more sense

They need several channels (e.g., cross-functional substreams) and you’d blow past the one-channel guest constraint.
Guest limit math doesn’t work – say you’ve only got 2 paid seats (so 10 free guests) but plan to involve 25 contractors.
Hard data separation – legal or client policies demand that outsiders not even appear in your main workspace’s user directory.

A middle path: Slack Connect

If the collaborators already have a paid Slack of their own, share a channel via Slack Connect. Both sides keep their own workspaces, you get full Pro features in the shared channel, and nobody pays extra seats. If they’re on Free, they still get a 30-day Pro trial in that channel, so it can bridge a short-term project at no cost. citeturn0search4

Quick rule of thumb for a ≤ 10-person core team

One-channel, limited-scope collab? → stick with single-channel guests (simpler, full features).
Multichannel project or > 5 × team size of outsiders? → create a Free project workspace (or use Slack Connect if they already pay).

Let me know roughly how many external collaborators and channels you expect, and we can nail down the cleanest setup.