How to fix Error: Error creating Service Bus: NamespaceAlreadyExists in Terraform

The simplest solution is to use a more unique name. Service Bus namespace names must be:
- Globally unique across Azure (not just your resource group or subscription)
- 6-50 characters long
- Lowercase letters, numbers, and hyphens only
- Cannot start or end with a hyphen
- Cannot contain consecutive hyphens

Try adding a unique identifier:

resource "azurerm_servicebus_namespace" "example" {
  name                = "myorg-myapp-${random_string.namespace_suffix.result}"
  location            = azurerm_resource_group.example.location
  resource_group_name = azurerm_resource_group.example.name
  sku                 = "Standard"
}

resource "random_string" "namespace_suffix" {
  length  = 4
  special = false
  upper   = false
}

This generates a unique suffix like "myorg-myapp-a7k2" to ensure global uniqueness.

If you recently deleted a namespace, it may still be in Azure's soft-delete recovery window (14 days). Check for soft-deleted namespaces using the Azure CLI:

az servicebus namespace exists --name your-namespace-name --resource-group your-resource-group

Or list all namespaces in your resource group:

az servicebus namespace list --resource-group your-resource-group -o table

If a soft-deleted namespace is blocking you, either:
1. Wait for the 14-day recovery period to expire automatically
2. Use a different namespace name now (faster option)
3. Purge the soft-deleted namespace immediately (via Azure Portal under "Deleted resources" in your resource group)

If the namespace already exists in Azure and you want Terraform to manage it (rather than creating a new one), use terraform import:

First, find the full resource ID of the existing namespace:

az servicebus namespace show --name your-existing-namespace --resource-group your-resource-group --query id -o tsv

Then import it into your Terraform state:

terraform import azurerm_servicebus_namespace.example /subscriptions/{subscription-id}/resourceGroups/{resource-group}/providers/Microsoft.ServiceBus/namespaces/{namespace-name}

After importing, update your Terraform configuration to match the existing resource, then run:

terraform plan

You should see no changes required if the configuration matches the existing resource.

Ensure you're authenticated to the correct Azure subscription and tenant where you want to create the namespace. Run:

az account show --query "id" -o tsv
az account show --query "tenantId" -o tsv

In your Terraform code, explicitly set the subscription if using multiple subscriptions:

provider "azurerm" {
  features {}
  subscription_id = "your-subscription-id"
}

Make sure your provider configuration matches the subscription where you want the namespace to exist. If you accidentally have the same namespace name in a different subscription, you may not see it in the Portal.

Verify if Terraform already thinks the namespace exists:

terraform state list | grep servicebus_namespace
terraform state show azurerm_servicebus_namespace.example

If the namespace is in your state but the error persists, refresh your state:

terraform refresh

If the namespace is NOT in your state but exists in Azure, import it using the previous step. If you want to completely recreate it:

terraform state rm azurerm_servicebus_namespace.example
terraform apply  # This will create a new one (if the name is available)

Caution: Using state rm without deleting the actual Azure resource will cause the old namespace to orphan (it won't be managed by Terraform anymore).

If the existing namespace is not needed, delete it from Azure before retrying:

Via Azure CLI:

az servicebus namespace delete --name your-namespace-name --resource-group your-resource-group

Via Azure Portal:
1. Navigate to your resource group
2. Find the Service Bus namespace
3. Click "Delete" and confirm

After deletion, wait 1-2 minutes for the name to fully release, then retry your Terraform deployment:

terraform apply

Note: Any queues, topics, or subscriptions within the namespace will be deleted as well. Ensure no applications depend on them first.