AWS Service Principals: The Complete Auto-Updated List (2025)

When working with AWS IAM policies and trust relationships, you need to know the exact service principal for each AWS service. This comprehensive reference provides instant access to all 450+ AWS service principals, making IAM policy development faster and more accurate.

What is an AWS Service Principal?

A service principal is an identifier that represents an AWS service. Service principals are used in IAM policies to grant AWS services permission to perform actions on your behalf. They're essential for:

• Trust policies that allow services to assume IAM roles
• Resource-based policies that grant services access to resources
• Service-linked roles that AWS services use to perform actions

Why Use This Service Principal Reference?

When creating IAM policies, you need to know the exact service principal format for each AWS service. While AWS documentation provides this information, it's scattered across hundreds of service-specific pages.

This cheat sheet solves that problem by consolidating every AWS service principal into a single, searchable reference - saving you hours of documentation hunting.

Quick IAM Trust Policy Example

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Principal": {
        "Service": "lambda.amazonaws.com"
      },
      "Action": "sts:AssumeRole"
    }
  ]
}

How to Use This Service Principal Guide

1. Search (Ctrl+F) for your AWS service (e.g., "lambda", "s3", "ec2")
2. Find the service principal in the second column
3. Click the documentation link for more details about IAM principals
4. Copy the service principal into your IAM policy or trust relationship
5. Configure your IAM policies with the correct service principal

Complete List of AWS Service Principals

The table below contains every AWS service principal, automatically fetched from the AWS Policy Generator and updated for 2025. Click the documentation link to learn more about IAM principals:

Total Unique Service Principals: 452 | With Documentation Links: 91 | Last Updated: December 2, 2025

Note: The data is automatically fetched from the official AWS Policy Generator and parsed into this markdown table using a custom Node.js script. The table is regularly updated to include the latest AWS services.

Common Use Cases for Service Principals

Service principals are commonly used in these scenarios:

1. Lambda Execution Roles: Allow Lambda to write logs to CloudWatch

   • Service Principal: lambda.amazonaws.com

2. EC2 Instance Profiles: Allow EC2 instances to call AWS services

   • Service Principal: ec2.amazonaws.com

3. ECS Task Roles: Enable ECS tasks to access AWS resources

   • Service Principal: ecs-tasks.amazonaws.com

4. CodeBuild Service Roles: Grant CodeBuild permissions to build projects

   • Service Principal: codebuild.amazonaws.com

5. EventBridge Rules: Allow EventBridge to invoke targets

   • Service Principal: events.amazonaws.com

Generate Service Principals in VS Code

If you prefer working directly in your IDE, I've created a VS Code extension that automatically generates IAM service principal snippets for you.

Instead of looking up this table every time, you can simply use the IAM Service Principal Snippets extension to autocomplete service principals directly in your IAM policies.

More Useful AWS Cheat Sheets, Lists and Tables

• AWS CloudFormation Resource Attributes - Complete reference of all CloudFormation resource types and their attributes
• AWS CloudFormation Resource Properties - Comprehensive table of all CloudFormation resource properties
• Amazon Resource Names (ARNs) - Complete reference list of ARNs for all AWS services
• AWS Trusted Advisor Cheat Sheet - Cheat Sheet containing a practical overview of checks that are being done by the AWS Trusted Advisor
• AWS IAM Documentation - Official guide to IAM policy principals