An Azure communication platform for deploying applications across devices and platforms.
A pre-cutoff ACS Email resource should not be treated as safely transferable to a new post-cutoff customer: current public documentation neither confirms that the Email Communication Service resource can be moved nor that grandfathered eligibility survives a change of subscription or customer.
What is documented
| Question | Documented answer |
|---|---|
| Move the general ACS resource between resource groups/subscriptions? | Microsoft.Communication/communicationServices supports resource-group and same-tenant subscription moves, subject to restrictions such as attached phone numbers. ^1^ |
| Move the Email Communication Service resource? | Not established. The move-support entry identifies communicationservices, but the supplied move table does not identify the separate Microsoft.Communication/emailServices resource type. It therefore cannot be assumed that the email service and its domain children are movable. |
| Preserve retirement eligibility after a move? | Not documented. The retirement guide says customers with an ACS resource created before October 23, 2026 can continue using their existing resources for current business workloads. It does not define whether eligibility follows the resource ID, original subscription, tenant, billing customer, or destination customer after a move. ^2^ |
| Is this new-customer onboarding? | Unresolved by published policy. The destination customer has no pre-cutoff ACS resource, which matches the group for which onboarding will be limited. The guide does not provide an exception for transferring a pre-created resource to such a customer. ^2^ |
| Direct cross-tenant resource move? | No. ARM subscription moves require source and destination subscriptions to belong to the same Microsoft Entra tenant. ^3^ |
| Terraform/ARM management after a move? | Normal ARM operations are documented, but continued availability of every operation during retirement—especially expansion, domain provisioning, quota changes, or recreation—is not guaranteed. |
| Recreate after deletion? | Deletion is permanent. Documentation does not promise that a deleted grandfathered resource can be recreated after the cutoff. ^4^ |
Important resource-model distinction
ACS Email normally involves multiple resources:
-
Microsoft.Communication/communicationServices -
Microsoft.Communication/emailServices - Domain child resources under the email service
- A link from the Communication Services resource to the verified domain
The move-support table confirms only the first resource type in the material available here. Child resources normally move with a movable parent, but emailServices is itself a separate top-level resource—not a child of communicationServices. Consequently, support for moving the general ACS resource does not prove support for moving the Email Communication Service or its verified domain.
Domain linking also uses full ARM resource IDs. A move changes the subscription/resource-group portions of those IDs, so links and other dependencies may need reconfiguration. ARM documentation explicitly states that moves change resource IDs and that dependencies with other resources can break. ^3^
Cross-tenant cases
A direct move to a subscription in another Entra tenant is unsupported. A possible Azure-level pattern is to transfer an entire subscription to another directory, but that is not the same operation as moving an individual ACS resource. Nothing in the retirement guide confirms that such a subscription transfer preserves ACS Email eligibility for a new customer.
Do not use subscription transfer as a workaround without written Product-team confirmation covering:
- the destination customer and tenant;
- the exact resource IDs and types;
- continued ACS Email eligibility through September 30, 2028;
- custom-domain and quota behavior.
ARM and Terraform implications if Microsoft approves the move
For an approved same-tenant move:
- Validate that every resource type in the ACS Email topology supports the move.
- Move all required dependent resources together.
- Update Terraform provider aliases and all subscription, resource-group, and resource-ID references.
- Import or move Terraform state rather than allowing Terraform to destroy and recreate resources.
- Run
terraform planand require a no-replacement result before applying. - Re-create resource-scoped RBAC assignments; Azure role assignments do not move with the resource. ^5^
- Recheck domain links and diagnostic settings, because each resource has its own diagnostic configuration. ^6^
Avoid any plan containing destroy/create actions:
terraform import '<resource-address>' '<new-resource-id>'
terraform plan -out=move-review.tfplan
terraform show move-review.tfplan
# Do not apply if ACS Email, its domain, or linked ACS resource
# is marked for replacement.
Required Product-team confirmation
Request a written determination that explicitly answers:
- whether
Microsoft.Communication/emailServicesand its domain children support the proposed move; - whether eligibility is resource-, subscription-, tenant-, or customer-scoped;
- whether transfer to a customer with no pre-cutoff ACS resource is prohibited onboarding or expansion;
- which post-cutoff ARM operations remain permitted;
- whether deletion ends grandfathered eligibility permanently.
Until those points are answered, the pre-provisioned pool is not a dependable onboarding strategy. Plan migration to a supported email service rather than contractually or operationally committing ACS Email to customers onboarded after the cutoff.
References