The ability to merge accounts is based on your access permissions within Matrix. If an account is being billed in other markets, it will not appear in your Localized Account Maintenance list for maintenance.
This restriction has been put in place so that the name of the account is not changed in the other markets without all parties approving the modification. This helps ensure the data is predictable and clean for all account stakeholders.
Local Account Maintenance restricts your access to only Rename, Merge or Group accounts that are within your data partition.
If an account needs maintenance that falls outside of your data partition access, please contact Matrix Support via firstname.lastname@example.org or Live Chat and we will be happy to take a look at your merge request.