aws-organizations

Control Tower gets you an org; it does not tell you how many OUs you need or which policy type owns VPC public access. Since re:Invent 2024 you have four layers — SCP, RCP, declarative, and tag policies — and RCP coverage grew through Feb 2026 (DynamoDB). A composite 60-account enterprise cut exception SCP attachments from 14 ad-hoc to 3 time-boxed RFCs in two quarters by moving accounts out of "temporary" prod OUs.

Your landing zone set up the org, OUs, and baseline SCPs — then most teams stall, duplicating resources per account and wiring brittle cross-account role chains. Since re:Invent 2024 the toolkit changed: RCPs bound what can be done TO a resource (even by external principals), declarative policies enforce EC2/VPC/EBS config state that survives new APIs, and one Route 53 Profile can push DNS to up to 5,000 VPCs. Here is the mechanism-by-job decision matrix and a rollout order that avoids lockouts.

Tag policies report; only an SCP prevents untagged spend. And ~21% of a typical bill — egress, inter-AZ transfer, Enterprise Support, shared platform services — carries no tag any tool can read. Here is the two-layer enforcement model, the Cost Categories split-charge rules that replace the monthly allocation spreadsheet, and why you show back before you charge back.

A CCoE that only publishes standards decks fails within two quarters. This 2026 operating model ties platform RFCs, delegated-admin guardrails, Well-Architected reviews, and FinOps chargeback—benchmarked on a 14-account estate that cut deploy exceptions from 23/month to 6 in 90 days.

CAF 3.0 organizes six perspectives and 47 capabilities—up from 31 in CAF 2.0—plus four phases (Envision, Align, Launch, Scale). Here is how to connect those workshops to Control Tower, MAP, and Well-Architected without treating the framework as a slide deck.

July 2026: nine migration mistakes that still show up after Migration Hub closed to new customers on November 7, 2025 — Application Migration Service (MGN), DMS, AWS Transform, Org/SCPs, FinOps dual-run costs, and Migration Lens.