AWS IAM Identity Center Explained | Manage Multiple AWS Accounts with SSO

One of the biggest problems in growing AWS environments is user management.

Initially, creating a few IAM users manually feels manageable.

But once multiple:

• AWS accounts,
• teams,
• developers,
• and environments

enter the picture, things become messy very quickly.

You start dealing with:

• duplicated IAM users,
• inconsistent permissions,
• long-term credentials,
• and manual access management.

That’s where:
Amazon Web Services IAM Identity Center becomes extremely useful.

In this guide, I’ll walk through the practical setup demonstrated in the video and explain how centralized AWS authentication works using IAM Identity Center (formerly AWS SSO).

What is AWS IAM Identity Center?

AWS IAM Identity Center is a centralized authentication and access management service.

Instead of creating separate IAM users in every AWS account,
users can:

• log in once,
• access multiple AWS accounts,
• and receive permissions centrally.

It works much more like:

Active Directory style authentication

rather than manually managing users account-by-account.

Why Traditional IAM User Management Becomes Difficult

When environments grow,
managing users manually becomes painful.

Example problems:

• duplicated users across accounts
• permission inconsistencies
• credential rotation issues
• poor visibility
• higher security risk

This becomes especially difficult in:

• multi-account AWS Organizations
• enterprise environments
• larger DevOps teams

IAM Identity Center Solves This

IAM Identity Center helps centralize:

• authentication
• authorization
• account access

Users authenticate once and can access multiple AWS accounts through a single portal.

That simplifies access management significantly.

The Goal of the Setup

The main objective of the project was:
👉 manage multiple AWS accounts securely from one centralized login system.

Instead of:

• manually creating IAM users everywhere,

the setup uses:

• centralized users
• centralized groups
• centralized permission assignments

This is much closer to how larger organizations manage AWS access.

Step 1: Enable IAM Identity Center

The first step was enabling IAM Identity Center inside AWS Organizations.

This creates:

• centralized access management
• SSO portal capability
• permission assignment workflows

Initially, the console may look slightly confusing, especially if you’ve only used standard IAM before.

Step 2: Configure Identity Source

Instead of using local IAM Identity Center users,
the setup uses:

AWS Managed Microsoft AD

as the identity source.

This allows user and group management through Active Directory.

Why Active Directory Matters

Many enterprise environments already use:

• Microsoft Active Directory
• centralized authentication systems

Connecting AWS access to AD makes user management much cleaner and more scalable.

Step 3: Create AWS Managed Microsoft AD

The setup then creates:

• AWS Managed Microsoft Active Directory

This becomes the centralized identity backend.

The directory handles:

• users
• groups
• authentication

inside AWS.

Important Cost Reminder

One thing beginners should know:

Managed Microsoft AD is NOT free.

Even testing environments can generate noticeable costs if forgotten.

Always clean up after testing.

Step 4: Launch Windows EC2 Instance

A Windows EC2 instance was launched to act as:
👉 the management server.

This machine helps manage:

• Active Directory users
• groups
• administrative tasks

Installing RSAT Tools

On the Windows server,
Remote Server Administration Tools (RSAT) were installed.

This allows:

• Active Directory management
• user creation
• group creation
• directory administration

directly from the EC2 instance.

Step 5: Join EC2 Instance to Domain

The Windows server was then joined to the Active Directory domain.

This is an important step because:

• the server becomes part of the directory environment
• centralized management becomes possible

Initially, domain joining can feel intimidating if you haven’t worked with AD before.

But once completed successfully, the workflow becomes much easier to understand.

Step 6: Create Users & Groups

Inside Active Directory:

• users
• groups

were created manually.

Example:

Developers
Admins
ReadOnlyUsers

This allows permission management through groups instead of configuring users individually.

That’s a much cleaner long-term approach.

Step 7: Synchronize with IAM Identity Center

After user and group creation,
the identities synchronize with IAM Identity Center.

Now AWS can:

• recognize users
• recognize groups
• assign permissions centrally

across AWS accounts.

Step 8: Create Permission Sets

Instead of attaching IAM policies directly to users,
IAM Identity Center uses:

Permission Sets

Examples:

• AdministratorAccess
• ReadOnlyAccess
• Custom DevOps Access

Permission Sets define what users can do inside accounts.

Why Permission Sets Are Useful

This approach becomes much easier to manage compared to:

• creating IAM users everywhere
• attaching random policies manually

You can:

• standardize access
• manage permissions centrally
• scale much more cleanly

Step 9: Assign Access to AWS Accounts

Users or groups can then be assigned to:

• specific AWS accounts
• specific roles
• specific permission sets

Example:

DevOps Team → Production Account → ReadOnly

This makes multi-account AWS management much more organized.

Step 10: User Login Experience

One of the coolest parts of IAM Identity Center is the user portal.

Users:

• log in once
• see all accessible AWS accounts
• click and enter accounts directly

without repeatedly entering credentials.

This creates a much cleaner SSO workflow.

Session Duration

The video also explains session durations.

Instead of permanent credentials,
users receive:

• temporary sessions
• temporary credentials

This is much safer than long-lived IAM access keys.

CLI Access

Another useful feature:
users can also obtain:

• temporary CLI credentials

This allows secure command-line access without storing permanent credentials locally.

That’s very useful in DevOps workflows.

What Helped Me Understand IAM Identity Center Better

Initially IAM Identity Center looked complicated because:

• multiple AWS accounts
• AD integration
• permission sets
• Organizations

all interact together.

But once I visualized:

Users → Groups → Permission Sets → AWS Accounts

the architecture became much clearer.

Common Beginner Mistakes

Some common issues during setup include:

• incorrect Security Group rules
• DNS problems
• improper directory setup
• permission assignment confusion
• syncing misunderstandings

Most authentication issues usually come down to:

• networking
• permissions
• identity source configuration

Important Cleanup Reminder

After testing:

• terminate Windows EC2
• delete Managed AD
• remove unused resources

because Managed Microsoft AD and Windows instances can generate costs quickly.

Full Video Walkthrough

I also created a complete hands-on walkthrough covering:

• IAM Identity Center setup
• AWS Managed Microsoft AD
• Windows EC2 setup
• RSAT installation
• domain joining
• user & group management
• Permission Sets
• SSO login flow
• AWS account assignments
• CLI access

along with practical AWS console demonstrations and troubleshooting explanations.

👉 Watch the full walkthrough here:

Why IAM Identity Center Matters

As AWS environments grow,
centralized authentication becomes extremely important.

IAM Identity Center helps improve:

• security
• scalability
• visibility
• user management
• operational simplicity

This is why larger organizations rely heavily on centralized identity systems.

Final Thoughts

Initially, IAM Identity Center can feel more complicated than simply creating IAM users manually.

But once multiple accounts and teams enter the picture,
centralized authentication becomes much easier to manage.

In my experience, understanding:

• Organizations,
• Permission Sets,
• and centralized identity management

helps AWS environments scale much more cleanly.

What You Should Learn Next

After understanding IAM Identity Center, explore:

• AWS Organizations
• SCPs (Service Control Policies)
• Cross-account IAM roles
• AWS Control Tower
• Identity federation
• Zero Trust access concepts

These concepts become much easier once centralized authentication is clear.

Bonus Tip

When learning AWS security,
don’t focus only on creating users.

Focus on:

• centralized access
• least privilege
• temporary credentials
• scalable permission management

That mindset becomes very valuable in real-world environments.

Related Guides

If you’re learning AWS and DevOps, also check:

• AWS WAF Explained
• OpenVPN + VPC Peering
• AWS Auto Scaling Explained
• Kubernetes Architecture Explained
• DevOps Roadmap 2026