You are trying out VMware Cloud on AWS – or are planning to do so in the future? That is great News!
But what to do with the SDDC, once you’ve – hopefully successful – tested your workloads on the Plattform and are planning to remove it, until you are ready to bring your Production workload?
Or in case you have created a new SDDC (e.g. with i3en Nodes, coming from an i3 based, or i3en mixed Cluster) and are in need to remove the existing one?
So, let me quickly outline the steps we’d recommend to go through, to cleanly remove your SDDC and to not have further costs incurred.
Did you use/test HCX?
If yes: Uninstall your HCX deployment first.
Follow the steps outlined in this KB Article, to cleanly remove HCX:
https://kb.vmware.com/s/article/74869
Delete the SDDC
Click on “Delete SDDC” within your Cloud Console. 
Before you can delete your SDDC, you’d need to acknowledge all the consequences this implies:
Link to VMC SDDC delete documentation (click).
After some time, your SDDC will be deleted and all data on the hosts will be securely wiped.
Unconfigure AWS components (if desired)
1. Remove (Private-/Public-/Transit-) VIF attachment in AWS connected VPC (there are costs per attachment, even if not being used)
2. Delete connected VPC, if needed/wished for. There are no costs for an AWS VPC itself. (You could leave this in place, in case you may decide on re-using it for later (production-) use.
3. Unconfigure (POC related) on-prem routing and firewall rule configurations
4. Remove manual routing configurations (if any)
5. Remove FW rules for example for vCenter access and HCX
What about my VMware ORG?
The VMC organization itself can remain and potentially being used later for a productive SDDC. This can save setup/deployment time in the future.
There are no costs associated to a VMware/VMC ORG, when there is no SDDC (or any other Cloud Solution) actively running.