In this guide · 8 sections
- 01Quick comparison: Google Chat vs Teams vs Slack
- 02What you actually pay on top of your email plan
- 03Guests and external chat: the security difference
- 04Message history, retention and leavers
- 05When Slack is worth paying for
- 06Moving the team off WhatsApp groups
- 07Do it yourself or get help?
- 08Frequently asked questions
Short answer
If you pay for Microsoft 365 Business Basic or above, use Teams; on Google Workspace, use Google Chat. Both cost nothing extra. Add Slack (Pro from US$8.75 per user a month, billed monthly) only if you work in many shared channels with clients or rely on its app integrations.
Quick comparison: Google Chat vs Teams vs Slack
The question for most small businesses is not which chat app is best in the abstract. It is whether the one bundled with your email is good enough, or whether Slack is worth a second bill.
Microsoft Teams
Bundled with Microsoft 365Included from US$7/user/mo
- Chat, channels, meetings and calls in one app
- Files stored in SharePoint and OneDrive
- Guest access and external chat with other organisations
- Managed in the same admin centre as email
Best for: Businesses already on Microsoft 365.
Google Chat
Bundled with WorkspaceIncluded from S$9.40/user/mo
- Direct messages and spaces inside Gmail
- Links naturally to Drive, Docs and Meet
- External chat that admins can limit to allowlisted domains
- Simpler feature set than Teams or Slack
Best for: Teams that live in Gmail and Google Docs.
Slack
Separate subscriptionFree; Pro US$8.75/user/mo monthly
- Best-known app directory and workflow tools
- Slack Connect channels shared with other companies
- Free plan: 90 days of history, 10 apps
- A second set of accounts to manage and offboard
Best for: Firms that live in shared channels with clients and tools.
Prices are from Microsoft's Teams comparison page for Singapore, Google Workspace pricing and Slack's Singapore pricing page, as of October 2026, before GST. Microsoft bills in US dollars; Google shows Singapore dollars.
What you actually pay on top of your email plan
Here is the extra cost for a team that already has business email, before GST.
| You already pay for | Teams | Google Chat | Slack Pro |
|---|---|---|---|
| Microsoft 365 Business Basic, Standard or Premium | Included | Not available | +US$8.75/user/mo |
| Google Workspace (any plan) | Teams Essentials US$4/user/mo | Included | +US$8.75/user/mo |
| Email from your web host only | Teams Essentials US$4/user/mo | Needs a Workspace plan | Free plan, or US$8.75/user/mo |
Slack's pricing page lists Business+ at US$18 per user a month billed monthly, and was running a three-month introductory discount on Pro and Business+ when checked. Microsoft's Teams page also shows plans with and without Teams, plus a Teams Premium add-on at US$10 per user a month for advanced meeting features most small teams do not need.
Guests and external chat: the security difference
All three let staff talk to people outside the company, which is where most risk sits. Attackers use external chat requests to impersonate IT support or suppliers, and guests often keep access long after a project ends.
- Teams separates guest access (an outsider added to your team with access to its files) from external access (chat and calls with users in other Microsoft 365 organisations). Admins can allow all domains, block some, or allow only listed ones.
- Google Chat has an External Chat Settings page in the Admin console. You can turn external messaging off, or allow it only with allowlisted domains, per organisational unit. See Google's external Chat admin help.
- Slack limits Slack Connect and external messages to one-to-one on the Free plan. Paid plans allow shared channels with other companies; guest accounts are managed by workspace admins.
Our guide to Teams external access and guest settings walks through the safe defaults for Microsoft 365.
Message history, retention and leavers
Slack's free plan only shows 90 days of messages and files. For a business that relies on chat for decisions and approvals, that limit alone usually forces a paid plan.
Teams and Google Chat keep history according to your tenant settings. If you need formal retention, legal hold or eDiscovery, those are tied to higher tiers: Google lists Vault in Business Plus, and Microsoft's retention and compliance features depend on your Microsoft 365 plan.
When Slack is worth paying for
Pay for Slack if
- Most of your work happens in shared channels with clients or partners
- You depend on integrations that are richer in Slack
- Your team is spread across companies using different email platforms
- You will set up single sign-on and proper offboarding
Stick with Teams or Google Chat if
- Chat is mainly internal
- You already pay for Microsoft 365 or Google Workspace
- Nobody has time to manage a second admin console
- You need one place for email, files and chat records
If the main problem is video calls rather than chat, see our comparison of Zoom vs Teams vs Google Meet. If you have not yet picked an email platform, our Microsoft 365 vs Google Workspace guide is the bigger decision, and chat follows from it.
Moving the team off WhatsApp groups
Many Singapore SMEs run internal chat on WhatsApp. It works until someone leaves with the group history on their personal phone. Our WhatsApp vs Slack vs Teams comparison covers that switch in more detail. The short version:
Pick the tool that comes with your email
Teams for Microsoft 365, Google Chat for Workspace. Avoid adding a new bill on day one.
Create a few channels or spaces, not dozens
Start with General, one per team, and one per active client or project.
Set external chat rules before inviting anyone
Allow only the client domains you need, and turn off auto-accept from unknown external users.
Install the mobile app on staff phones
Use the work account and enable app protection or device management if staff use personal phones.
Move one workflow at a time
Start with leave requests or daily updates, then retire the matching WhatsApp group.
Do it yourself or get help?
Switching on Teams or Google Chat is easy. Setting the guest and external rules, mobile access and leaver process correctly is where small businesses slip.
Our Business Email Setup (S$249) sets up Microsoft 365 or Google Workspace in your company's name with chat ready to use. The Microsoft 365 / Google Security Lockdown (S$590) sets external chat and guest access to allow-list mode, enforces MFA and documents how to remove leavers.
Frequently asked questions
Teams is included in Microsoft 365 Business Basic, Standard and Premium, with no extra charge, according to Microsoft's Singapore Teams page in October 2026. Business Basic is US$7 per user a month paid yearly, before GST. Microsoft also sells versions without Teams, so check the plan name when you buy.
Yes, if your admin allows it. In the Google Admin console, under Google Chat, External Chat Settings, an admin can turn external messaging on or off and optionally limit it to allowlisted domains. A separate setting controls whether users can create spaces and group messages that include outsiders.
Slack's Singapore pricing page in October 2026 lists the Free plan at no cost with 90 days of message history, Pro at US$8.75 per user a month billed monthly and Business+ at US$18 per user a month billed monthly, before GST. Enterprise pricing is by quote. Slack was also running a three-month introductory discount.
Not directly. Teams external access works with other Microsoft Teams organisations, and Google Chat external chat works with other Google accounts. To talk across platforms, people usually invite each other as guests, use email, or use a shared Slack Connect channel if both sides have Slack.