How to fix Error: Error creating Cognito User Pool: LimitExceededException in Terraform

TerraformINTERMEDIATEMEDIUMUpdated Dec 31, 2025· 95 views

AWS Cognito enforces quotas on user pools, operations, and API request rates per region. This error occurs when you exceed your account's default limits. Resolve it by requesting a quota increase or optimizing your deployment strategy.

Quick fix

Fixes LimitExceededException

aws cognito-idp list-user-pools --max-results 60 --region us-east-1
  1. Check your current Cognito user pool count
  2. Review your Terraform state for duplicate resources
  3. Consolidate unnecessary user pools
  4. Request an AWS quota increase
terraform — error
aws cognito-idp list-user-pools --max-results 60 --region us-east-1
Error: Error creating Cognito User Pool: LimitExceededException

What this error means

Amazon Cognito implements quota limits to prevent abuse and manage resource allocation across accounts. When you encounter a LimitExceededException while creating a Cognito User Pool with Terraform, it means your AWS account has reached one of several type of limits: 1. **User pool quota per region**: By default, you can create up to 1,000 user pools per AWS region per account. Each region has independent quotas. 2. **API request rate limits**: Cognito restricts certain operations to 5 requests per second (RPS) per user pool by default. User authentication operations are limited to 120 RPS per region across all pools. 3. **User pool configuration limits**: Individual user pools have limits on resources like custom attributes, groups, resource servers, and identity providers. When Terraform attempts to create a Cognito User Pool and hits any of these limits, AWS returns a LimitExceededException and the `aws_cognito_user_pool` resource creation fails.

Typical symptoms

  • Terraform apply fails with 'LimitExceededException' error when creating aws_cognito_user_pool
  • Error message includes 'Exceeded the limit' or mentions quota limits
  • Previously successful Terraform deployments suddenly fail without code changes
  • Error occurs consistently when applying the same configuration
  • User pool creation works in AWS Console but fails through Terraform

Common causes

  1. You have already created the maximum of 1,000 user pools in the target AWS region
  2. Your AWS account is hitting the API request rate limit for Cognito operations in the region
  3. Terraform state is out of sync with actual AWS resources, attempting to create a duplicate pool
  4. The user pool configuration exceeds limits on sub-resources like custom attributes or groups
  5. Regional quota exhaustion due to automated testing, CI/CD pipelines, or multiple environments

How to fix "Error: Error creating Cognito User Pool: LimitExceededException"

1Check your current Cognito user pool count

Log into your AWS Console and navigate to Amazon Cognito. Count existing user pools in the affected region, or use the AWS CLI:

bash
aws cognito-idp list-user-pools --max-results 60 --region us-east-1

This lists all user pools in the specified region. Remember that Cognito quotas are per-region per-account, so a pool in us-east-1 doesn't count toward quotas in us-west-2.

2Review your Terraform state for duplicate resources

Check if Terraform is trying to create a duplicate user pool:

bash
terraform state list | grep aws_cognito_user_pool

If the pool already exists in state but you're getting an error, refresh your state:

bash
terraform refresh

If the pool exists in AWS but not in your Terraform state, import it:

bash
terraform import aws_cognito_user_pool.example <user-pool-id>

Get the user pool ID from the AWS Cognito Console.

3Consolidate unnecessary user pools

If you have reached the 1,000 user pool limit, check if you can consolidate:

bash
# List all user pools with basic info
aws cognito-idp list-user-pools --max-results 60 --region us-east-1 --query 'UserPools[*].[Id,Name,CreationDate]' --output table

Review which pools are:
- Development or testing pools no longer in use
- Duplicate pools created by accident or automation
- Pools serving the same purpose

Delete unused pools via the AWS Console or CLI:

bash
aws cognito-idp delete-user-pool --user-pool-id <pool-id> --region us-east-1

Deleting a pool frees up the quota immediately.

4Request an AWS quota increase

If you legitimately need more user pools, request a quota increase:

1. Go to AWS Service Quotas console: https://console.aws.amazon.com/servicequotas
2. Search for "Cognito"
3. Find "User pools per region" or "User pools"
4. Click on the quota and select "Request quota increase"
5. Enter your desired value (AWS typically allows increases up to 10,000+ pools)
6. Submit the request

AWS usually approves quota increase requests within minutes to a few hours. You'll receive an email confirmation. Note that quota increases are per-region, so you may need separate requests for each region you use.

5Optimize API request patterns

If the error is related to API request rate limits rather than pool count, optimize your deployment:

bash
# Check if you're hitting rate limits (look for TooManyRequestException in CloudWatch)
aws logs filter-log-events --log-group-name /aws/cognito/<pool-name> --filter-pattern TooManyRequestException --region us-east-1

In your Terraform configuration, implement retry logic or stagger resource creation:

hcl
resource "aws_cognito_user_pool" "example" {
  name = "my-pool"
  # ... other config

  timeouts {
    create = "10m"
    update = "10m"
    delete = "10m"
  }
}

In your application, implement exponential backoff for API calls and cache authentication tokens to reduce request volume.

6Verify quota increase and retry deployment

Once your quota increase is approved, retry your Terraform deployment:

bash
terraform plan
terraform apply

If using CI/CD pipelines, ensure:
- Your AWS credentials have permissions to create Cognito user pools
- Your pipeline has the latest credentials with updated quotas
- Multiple parallel deployments are not creating duplicate pools

Consider adding a delay between resource creation in large deployments to avoid rate limit issues:

bash
terraform apply -parallelism=1

Advanced notes

Per-region quota isolation: Each AWS region maintains independent quotas for Cognito. You can create 1,000 user pools in us-east-1 AND another 1,000 in us-west-2. However, API rate limits (like UserAuthentication at 120 RPS) are per-region global limits across all your pools.

Request rate limits vs. resource limits: There are two different types of limits you might hit. Resource limits are about how many things you can create (pools, users, etc.). Request rate limits are about how fast you can call APIs. The error message usually indicates which type you've exceeded.

CI/CD pipeline automation: If you're using Terraform in automated pipelines, be careful not to repeatedly create and destroy pools in loops. Each creation counts toward quotas. Consider using Terraform workspaces to avoid duplicate pool creation or implement proper state locking with a remote backend.

Monthly Active Users (MAUs): While MAUs don't cause LimitExceededException for pool creation, they affect pricing and performance throttling. AWS Cognito is free for the first 50,000 MAUs, then charges per MAU. Beyond 2 million MAUs, you may experience automatic request throttling.

Service quotas management: AWS now provides the Service Quotas console where you can see real-time utilization, set up CloudWatch alarms, and automate quota increase requests. Enable this for Cognito to proactively monitor your quota consumption.

Frequently asked questions

What does "LimitExceededException" mean?
Amazon Cognito implements quota limits to prevent abuse and manage resource allocation across accounts. When you encounter a LimitExceededException while creating a Cognito User Pool with Terraform, it means your AWS account has reached one of several type of limits: 1. User pool quota per region: By default, you can create up to 1,000 user pools per AWS region per account.
How do I fix "LimitExceededException"?
AWS Cognito enforces quotas on user pools, operations, and API request rates per region. This error occurs when you exceed your account's default limits. Resolve it by requesting a quota increase or optimizing your deployment strategy.
What causes "LimitExceededException"?
You have already created the maximum of 1,000 user pools in the target AWS region Your AWS account is hitting the API request rate limit for Cognito operations in the region Terraform state is out of sync with actual AWS resources, attempting to create a duplicate pool
Is the "LimitExceededException" error serious?
It is a medium-severity error — more of a blocker than a risk. The steps above resolve it.

Official resources & further reading