Service Control Policies

Service Control Policies (SCPs) define the maximum permissions available to identities in member accounts. The Data Landing Zone composes SCPs from three additive tiers and ships a library of vetted preset statements you can drop in.

Composition model

SCPs in DLZ are composed from three tiers. All tiers are additive only — a tier cannot weaken or remove statements from a tier above it.

Tier	Applies to	Configured via
Org baseline	Every workload account	`scpBaselineStatements`
Per-account-type	All accounts of one type	`scpStatementsByAccountType.{development \| production}`
Per-account	One specific account	`DLzAccount.scpStatements`

The mandatory-tags SCP is always appended after the org baseline and cannot be opted out of.

SCP preset library

DLZ ships a library of preset statements covering common deny patterns. Each preset returns an iam.PolicyStatement you can compose into any tier. Presets exempt the Control Tower execution role automatically where required.

Preset	Purpose
`ScpDenyActionsOutsideRegions`	Deny regional API calls outside an allow-list (global services exempt).
`ScpDenyServiceActions`	Deny a caller-supplied list of `service:action` strings.
`ScpDenyDisablingSecurityServices`	Block disabling GuardDuty, Macie, Security Hub, Config, CloudTrail, etc.
`ScpDenyLeavingOrganization`	Block `organizations:LeaveOrganization`.
`ScpDenyRootUserActions`	Block actions performed by the account root user.
`ScpDenyRootCredentialsManagementInMemberAccounts`	Block management of root credentials in member accounts.
`ScpDenyIamWithoutPermissionsBoundary`	Require a permissions boundary on all IAM principals.
`ScpDenyS3PublicAccessBypass`	Block bypassing S3 Block Public Access settings.
`ScpDenyS3ObjectLockAndRetention`	Block tampering with S3 Object Lock and retention.
`ScpDenyBackupVaultLock`	Block tampering with AWS Backup Vault Lock.
`ScpDenyGlacierVaultLock`	Block tampering with S3 Glacier Vault Lock.
`ScpDenyMarketplaceSubscriptions`	Block AWS Marketplace subscription changes.
`ScpDenyDomainRegistrations`	Block Route53 domain registrations and transfers.
`ScpDenyDedicatedInfraAndSubscriptions`	Block dedicated hosts, capacity reservations, and similar commitments.
`ScpDenyReservedCapacityPurchases`	Block purchasing reserved capacity (EC2 RIs, etc.).
`ScpDenySavingsPlanPurchases`	Block purchasing Savings Plans.
`ScpDenyBedrockProvisionedThroughput`	Block creating Bedrock Provisioned Throughput.
`ScpDenyCfnStacksWithoutStandardTags`	Require mandatory tags on CloudFormation stacks (always appended).

Defining a baseline

Use scpBaselineStatements for full control over the org baseline. Compose it from presets and your own statements.

TypeScript
Python

import { App } from 'aws-cdk-lib';
import {
  DataLandingZone,
  ScpDenyActionsOutsideRegions,
  ScpDenyDisablingSecurityServices,
  ScpDenyLeavingOrganization,
  ScpDenyRootUserActions,
  ScpDenyServiceActions,
} from 'aws-data-landing-zone';

const app = new App();
const dlz = new DataLandingZone(app, {
  scpBaselineStatements: [
    ScpDenyActionsOutsideRegions.statement(['eu-west-1', 'eu-central-1']),
    ScpDenyDisablingSecurityServices.statement(),
    ScpDenyLeavingOrganization.statement(),
    ScpDenyRootUserActions.statement(),
    ScpDenyServiceActions.statement(['ecs:*', 'workspaces:*']),
  ],
 ...
});

import aws_cdk as cdk
import aws_data_landing_zone as dlz

app = cdk.App()
dlz.DataLandingZone(app,
    scp_baseline_statements=[
        dlz.ScpDenyActionsOutsideRegions.statement(["eu-west-1", "eu-central-1"]),
        dlz.ScpDenyDisablingSecurityServices.statement(),
        dlz.ScpDenyLeavingOrganization.statement(),
        dlz.ScpDenyRootUserActions.statement(),
        dlz.ScpDenyServiceActions.statement(["ecs:*", "workspaces:*"]),
    ],
    ...
)

Layering by account type

Apply additional restrictions to all accounts of one type via scpStatementsByAccountType. For example, prevent production accounts from purchasing long-term commitments while leaving development accounts unrestricted:

TypeScript
Python

import {
  DataLandingZone,
  ScpDenyReservedCapacityPurchases,
  ScpDenySavingsPlanPurchases,
} from 'aws-data-landing-zone';

const dlz = new DataLandingZone(app, {
  scpStatementsByAccountType: {
    production: [
      ScpDenyReservedCapacityPurchases.statement(),
      ScpDenySavingsPlanPurchases.statement(),
    ],
  },
 ...
});

dlz.DataLandingZone(app,
    scp_statements_by_account_type={
        "production": [
            dlz.ScpDenyReservedCapacityPurchases.statement(),
            dlz.ScpDenySavingsPlanPurchases.statement(),
        ],
    },
    ...
)

Per-account extras

Use scpStatements on a DLzAccount for one-off restrictions that only apply to a single account.

TypeScript
Python

import * as iam from 'aws-cdk-lib/aws-iam';

const dlz = new DataLandingZone(app, {
  organization: {
    ous: {
      workloads: {
        accounts: [
          {
            name: 'data-prod',
            type: DlzAccountType.PRODUCTION,
            scpStatements: [
              new iam.PolicyStatement({
                sid: 'DenyDynamoDBDelete',
                effect: iam.Effect.DENY,
                actions: ['dynamodb:DeleteTable'],
                resources: ['*'],
              }),
            ],
            ...
          },
        ],
      },
      ...
    },
    ...
  },
 ...
});

from aws_cdk import aws_iam as iam

dlz.DataLandingZone(app,
    organization=dlz.DLzOrganization(
        ous=dlz.OrgOus(
            workloads=dlz.OrgOuWorkloads(
                accounts=[
                    dlz.DLzAccount(
                        name="data-prod",
                        type=dlz.DlzAccountType.PRODUCTION,
                        scp_statements=[
                            iam.PolicyStatement(
                                sid="DenyDynamoDBDelete",
                                effect=iam.Effect.DENY,
                                actions=["dynamodb:DeleteTable"],
                                resources=["*"],
                            ),
                        ],
                        ...
                    ),
                ],
            ),
            ...
        ),
        ...
    ),
    ...
)

Validation

DLZ validates each account’s resolved SCP at synthesis time and fails with a clear error if:

the resolved policy is empty (AWS rejects empty policies)
more than 5 SCPs would be attached to the account
the policy body exceeds 5120 bytes

This catches misconfiguration before any CloudFormation deployment runs.