How to fix Error creating NAT Gateway: NatGatewayLimitExceeded in Terraform

Log into the AWS Console and navigate to the VPC service. Click on NAT gateways to see all gateways in your region. Count how many exist in each Availability Zone and note which ones are in Deleting status. This tells you how much quota you're consuming.

Alternatively, use the AWS CLI:

aws ec2 describe-nat-gateways --region us-east-1 \
  --query 'NatGateways[*].[NatGatewayId,State,SubnetId]' \
  --output table

If you see NAT gateways in Deleting state, these still count against your quota. Wait 2-5 minutes for them to transition to Deleted state, then they won't consume quota. Verify completion with:

aws ec2 describe-nat-gateways --region us-east-1 \
  --filter "Name=state,Values=deleted" \
  --query 'NatGateways[*].NatGatewayId'

If you have NAT gateways that are no longer needed, delete them to free up quota. First verify nothing depends on them by checking route tables:

aws ec2 describe-route-tables --region us-east-1 \
  --query "RouteTables[?Routes[?NatGatewayId=='nat-12345678']].RouteTableId"

Then delete via the console or CLI:

aws ec2 delete-nat-gateway --nat-gateway-id nat-12345678 --region us-east-1

Review your Terraform code to ensure you're not creating more NAT gateways than necessary. Use module options to limit creation:

module "vpc" {
  source = "terraform-aws-modules/vpc/aws"
  
  # Option 1: Single NAT gateway for entire VPC (cost-effective but less resilient)
  single_nat_gateway = true
  
  # Option 2: One NAT gateway per availability zone (recommended)
  one_nat_gateway_per_az = true
  
  # Avoid: Creating one NAT gateway per private subnet
  # This consumes quota quickly and is unnecessary
}

If you legitimately need more than 5 NAT gateways per AZ:

1. Go to the AWS Service Quotas console: https://console.aws.amazon.com/servicequotas
2. Search for "NAT gateways per Availability Zone"
3. Click on the quota and select "Request quota increase"
4. Enter the desired value (AWS typically approves reasonable increases)
5. Submit the request and wait for approval

Alternatively, use the CLI:

aws service-quotas request-service-quota-increase \
  --service-code vpc \
  --quota-code L-FE5A380F \
  --desired-value 10 \
  --region us-east-1

Once you've freed up quota or received approval for an increase, retry your Terraform deployment:

terraform plan
terraform apply

If using destroy and recreate, wait for all resources to fully delete before reapplying:

terraform destroy
# Wait 2-5 minutes
terraform apply