Prepare your Microsoft 365 tenant
If you are a Microsoft 365 subscriber, you can develop apps for Microsoft Teams with one of the following plans:
- Enterprise E1, E3, and E5
- Education, Education Plus, and Education E5
Microsoft Teams will also be available to customers who subscribed to E4 prior to its retirement.
Just need a development environment?
If you don't currently have a Microsoft 365 account, you can sign up for a Microsoft 365 Developer Program subscription. It's free for 90 days and will continually renew as long as you're using it for development activity. If you have a Visual Studio Enterprise or Professional subscription, both programs include a free Microsoft 365 developer subscription, active for the life of your Visual Studio subscription. See Set up a Microsoft 365 developer subscription.
Enable Microsoft Teams for your organization
If Microsoft Teams has not been enabled for your organization, you'll need to do that first. Take a look at our detailed guidance for enabling Teams for your organization.
Enable custom Teams apps and turn on custom app uploading
Turn on custom app sideloading for your developer tenant as follows:
Login to Microsoft 365 admin center with your admin credential.
Select Show All --> Teams.
It can take up to 24 hours for the "Teams" option to appear. During interim, you can Upload your custom app to a Teams environment for testing and validation.
- Navigate to Teams apps --> Setup Policies --> Global(Org-wide default)
- Toggle upload custom apps to the on position.
That's it! Your test tenant will now allow custom app sideloading.
It can take up to 24 hours before sideloading is enabled. During interim, you can use upload for <your tenant> to test your app.
For complete information on how these settings interact, See, Manage custom app policies and settings in Microsoft Teams and Manage app setup policies in Microsoft Teams.