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Fix Terraform Error: VpcLimitExceeded

Fix terraform VpcLimitExceeded errors. Check current VPC usage, delete unused VPCs, request quota increase

LLuca Berton1 min read

Quick Answer

# 
# Check current VPC count
aws ec2 describe-vpcs --query 'length(Vpcs)'
 
# Check quota
aws service-quotas get-service-quota \
  --service-code vpc \
  --quota-code L-F678F1CE

The Error

# 
Error: creating VPC: VpcLimitExceeded: The maximum number of VPCs has been reached.
  status code: 400

What Causes This

#

AWS limits VPCs to 5 per region by default. Common quota consumers:

  • Default VPC (1, created automatically)
  • Dev/staging/prod VPCs
  • Test VPCs that were never cleaned up
  • Each Terraform workspace creating its own VPC

Solution 1: Find and Delete Unused VPCs

# 
# List all VPCs with name and resource count
aws ec2 describe-vpcs \
  --query 'Vpcs[].{ID:VpcId,CIDR:CidrBlock,Name:Tags[?Key==`Name`].Value|[0],Default:IsDefault}' \
  --output table
-----------------------------------------------------------------
|                       DescribeVpcs                            |
+----------+-----------------+-----------+----------------------+
|   CIDR   |     Default     |    ID     |        Name          |
+----------+-----------------+-----------+----------------------+
| 172.31.0 |     True        | vpc-aaa   |  None (default)      |
| 10.0.0.0 |     False       | vpc-bbb   |  prod                |
| 10.1.0.0 |     False       | vpc-ccc   |  staging             |
| 10.2.0.0 |     False       | vpc-ddd   |  dev                 |
| 10.3.0.0 |     False       | vpc-eee   |  test-old            | ← Delete?
+----------+-----------------+-----------+----------------------+

Check if a VPC has resources before deleting:

VPC_ID="vpc-eee"
 
# Check for instances
aws ec2 describe-instances --filters "Name=vpc-id,Values=$VPC_ID" \
  --query 'length(Reservations[].Instances[])'
 
# Check for subnets
aws ec2 describe-subnets --filters "Name=vpc-id,Values=$VPC_ID" \
  --query 'length(Subnets)'
 
# Check for NAT Gateways
aws ec2 describe-nat-gateways --filter "Name=vpc-id,Values=$VPC_ID" \
  --query 'length(NatGateways[?State!=`deleted`])'

If empty, delete via Terraform or AWS CLI:

terraform destroy -target=module.test_vpc

Solution 2: Request Quota Increase

# 
# Check current limit
aws service-quotas get-service-quota \
  --service-code vpc \
  --quota-code L-F678F1CE \
  --query 'Quota.Value'
 
# Request increase to 10
aws service-quotas request-service-quota-increase \
  --service-code vpc \
  --quota-code L-F678F1CE \
  --desired-value 10

Or via Console: Service Quotas → VPC → VPCs per Region → Request increase

Increases to 10-20 are usually approved within hours.

Solution 3: Consolidate Into Fewer VPCs

#

Instead of one VPC per workload, use subnets:

# One VPC, multiple subnet groups
resource "aws_vpc" "shared" {
  cidr_block = "10.0.0.0/16"
}
 
# App A subnets
resource "aws_subnet" "app_a" {
  count      = 2
  vpc_id     = aws_vpc.shared.id
  cidr_block = cidrsubnet("10.0.0.0/16", 8, count.index)     # 10.0.0.0/24, 10.0.1.0/24
}
 
# App B subnets
resource "aws_subnet" "app_b" {
  count      = 2
  vpc_id     = aws_vpc.shared.id
  cidr_block = cidrsubnet("10.0.0.0/16", 8, count.index + 10) # 10.0.10.0/24, 10.0.11.0/24
}

Use security groups for isolation between workloads in the same VPC.

Solution 4: Check All Regions

#

VPC limits are per-region. Your other regions may have leftover VPCs:

for region in us-east-1 us-west-2 eu-west-1 eu-central-1 ap-southeast-1; do
  count=$(aws ec2 describe-vpcs --region $region --query 'length(Vpcs)')
  echo "$region: $count VPCs"
done

Solution 5: Clean Up Default VPCs

#

If you don't use EC2-Classic or need the default VPC:

# The default VPC uses 1 of your 5 slots
# You can delete it (but can recreate later)
aws ec2 delete-vpc --vpc-id vpc-default123

To recreate later: aws ec2 create-default-vpc

Hands-On Courses

#

Conclusion

#

AWS limits VPCs to 5 per region. Delete unused test VPCs, request a quota increase (usually approved quickly), or consolidate workloads into fewer VPCs with separate subnet groups. Check all regions for forgotten VPCs.

#Terraform#Troubleshooting#DevOps#Error Fix#AWS

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