Service principals vs service accounts: Which one should you use for Power Automate flows?

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Power Automate allows you to automate workflows across various applications and services. However, when you create a flow, you need to decide how to authenticate and authorize it to access the data sources and actions it needs. This is where service principals and service accounts come in.

Service principals are special types of users that represent an Azure AD application. They have a system administrator role and use a client secret (a permanent password) to connect to data sources such as Dataverse. Service accounts are regular user accounts that have a username and password. They can be assigned different roles and licenses depending on the flow’s needs.

Recently, I posted How to use service accounts in Power Automate flows and avoid common pitfalls. Check it out to do a deeper dive on just service accounts.

So which one should you use for your Power Automate flows: service principals or service accounts? Here are some pros and cons of each option:

Service PrincipalsService Accounts
Pros:Pros:
– More secure as they do not expose username or password– Easier to set up and manage
– Do not consume a license as they use an application user account– Can be assigned different roles and licenses for different flows
– Can perform actions on behalf of organization users who trigger the flow– Can access more data sources and actions than service principals
Cons:Cons:
– More complex to configure and troubleshoot– Less secure as they expose username or password
– Limited to data sources that support Azure AD authentication– Consume a license for each service account used in a flow
Table comparing the pros and cons of Service Principals and Service Accounts

As you can see, there is no definitive answer to which option is better for your Power Automate flows. It depends on your specific scenario, requirements, and preferences. However, some general guidelines are:

  • Use service principals if you want more security, less licensing costs, and more flexibility in performing actions on behalf of other users.
  • Use service accounts if you want more simplicity, more data source options, and more control over roles and licenses.

This post has explained the high-level differences between service principals and service accounts to consider when building flows in Power Automate. For more information, please refer to these resources: