Hey @Danny Wong
From the materials I'm coming across [1] [2], this isn't possible.
You can try the following policy, but it has to be tested. In the meantime, feel free to reach out to me on Teams. If I come across any updates, I'll be sure to post them.
{
"properties": {
"displayName": "Prevent Subscription Creation",
"policyType": "Custom",
"mode": "All",
"description": "This policy prevents users from creating subscriptions directly under the tenant level.",
"parameters": {
"effect": {
"type": "String",
"metadata": {
"displayName": "Effect",
"description": "Enable or disable the execution of the policy"
},
"allowedValues": [
"Deny",
"Disabled"
],
"defaultValue": "Deny"
}
},
"policyRule": {
"if": {
"allOf": [
{
"field": "type",
"equals": "Microsoft.Subscription/subscriptions"
},
{
"field": "Microsoft.Subscription/subscriptions/tenantId",
"equals": "[parameters('tenantId')]"
}
]
},
"then": {
"effect": "[parameters('effect')]"
}
}
}
}