Multi-Account Cloud Architecture with Terraform: AWS Organizations, Azure Management Groups, and GCP Organizations

Calendar February 22, 2026
Infrastructure
Advanced
Multi-Account-Terraform, Landing-Zone-Design, Cross-Account-Patterns, Provider-Aliasing
Terraform, Multi-Account, Aws-Organizations, Azure-Management-Groups, Gcp-Organizations, Landing-Zone, Cross-Account, Provider-Aliasing, State-Isolation
Terraform, Aws-Cli, Az, Gcloud

Multi-Account Cloud Architecture with Terraform#

Single-account cloud deployments work for learning and prototypes. Production systems need multiple accounts (AWS), subscriptions (Azure), or projects (GCP) for isolation — security boundaries, blast radius control, billing separation, and compliance requirements.

Terraform manages multi-account architectures well, but the patterns differ significantly from single-account work. Provider configuration, state isolation, cross-account references, and IAM trust relationships all need explicit design.

Why Multiple Accounts#

ReasonSingle Account ProblemMulti-Account Solution
Blast radiusMisconfigured IAM affects everythingDamage limited to one account
BillingCannot attribute costs to teamsPer-account billing and budgets
CompliancePCI data mixed with dev workloadsSeparate accounts for regulated workloads
Service limitsVPC limit of 5 per region sharedEach account has its own limits
Access controlComplex IAM policies to isolate teamsAccount boundary is the strongest isolation
TestingDev resources can affect productionImpossible for dev to touch prod resources

AWS Organizations#

Organization Structure#

Organization Root
├── Core OU
│   ├── Management Account (billing, org management)
│   ├── Security Account (GuardDuty, SecurityHub, audit logs)
│   └── Networking Account (Transit Gateway, shared VPCs)
├── Workload OU
│   ├── Production OU
│   │   ├── App-A Production Account
│   │   └── App-B Production Account
│   └── Non-Production OU
│       ├── App-A Development Account
│       └── App-A Staging Account
└── Sandbox OU
    └── Developer Sandbox Accounts

Terraform for AWS Organizations#

resource "aws_organizations_organization" "main" {
  feature_set = "ALL"

  enabled_policy_types = [
    "SERVICE_CONTROL_POLICY",
    "TAG_POLICY",
  ]
}

resource "aws_organizations_organizational_unit" "core" {
  name      = "Core"
  parent_id = aws_organizations_organization.main.roots[0].id
}

resource "aws_organizations_organizational_unit" "workloads" {
  name      = "Workloads"
  parent_id = aws_organizations_organization.main.roots[0].id
}

resource "aws_organizations_organizational_unit" "production" {
  name      = "Production"
  parent_id = aws_organizations_organizational_unit.workloads.id
}

# Create a workload account
resource "aws_organizations_account" "app_production" {
  name      = "app-a-production"
  email     = "aws+app-a-prod@example.com"
  parent_id = aws_organizations_organizational_unit.production.id
  role_name = "OrganizationAccountAccessRole"  # cross-account admin role

  lifecycle {
    prevent_destroy = true  # accounts cannot be easily recreated
  }
}

Service Control Policies (SCPs)#

SCPs set permission boundaries for entire OUs: