diff --git a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountByDepartment.json b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountByDepartment.json
index cc5a36e0c5ff..da318f9b18c0 100644
--- a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountByDepartment.json
+++ b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountByDepartment.json
@@ -8,7 +8,7 @@
   "responses": {
     "200": {
       "body": {
-        "id": "/providers/Microsoft.Billing/billingAccounts/6564892/enrollmentAccounts/257698",
+        "id": "/providers/Microsoft.Billing/billingAccounts/6564892/departments/164821/enrollmentAccounts/257698",
         "name": "257698",
         "properties": {
           "costCenter": "C0",
@@ -21,7 +21,7 @@
           "startDate": "2018-05-01T17:32:28Z",
           "endDate": "2019-05-31T17:32:28Z"
         },
-        "type": "Microsoft.Billing/billingAccounts/enrollmentAccounts"
+        "type": "Microsoft.Billing/billingAccounts/departments/enrollmentAccounts"
       }
     }
   }
diff --git a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountsListByDepartment.json b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountsListByDepartment.json
index 7ed7d9af4c23..a00413552a1c 100644
--- a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountsListByDepartment.json
+++ b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/examples/enrollmentAccountsListByDepartment.json
@@ -9,7 +9,7 @@
       "body": {
         "value": [
           {
-            "id": "/providers/Microsoft.Billing/billingAccounts/6564892/enrollmentAccounts/257698",
+            "id": "/providers/Microsoft.Billing/billingAccounts/6564892/departments/164821/enrollmentAccounts/257698",
             "name": "257698",
             "properties": {
               "costCenter": "C0",
@@ -22,10 +22,10 @@
               "startDate": "2018-05-01T17:32:28Z",
               "endDate": "2019-05-31T17:32:28Z"
             },
-            "type": "Microsoft.Billing/billingAccounts/enrollmentAccounts"
+            "type": "Microsoft.Billing/billingAccounts/departments/enrollmentAccounts"
           },
           {
-            "id": "/providers/Microsoft.Billing/billingAccounts/6564892/enrollmentAccounts/264698",
+            "id": "/providers/Microsoft.Billing/billingAccounts/6564892/departments/164821/enrollmentAccounts/264698",
             "name": "264698",
             "properties": {
               "costCenter": "C1",
@@ -38,7 +38,7 @@
               "startDate": "2018-05-01T17:32:28Z",
               "endDate": "2019-05-31T17:32:28Z"
             },
-            "type": "Microsoft.Billing/billingAccounts/enrollmentAccounts"
+            "type": "Microsoft.Billing/billingAccounts/departments/enrollmentAccounts"
           }
         ]
       }
diff --git a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/types.json b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/types.json
index 28a27bc1c09e..46bf506a6eee 100644
--- a/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/types.json
+++ b/specification/billing/resource-manager/Microsoft.Billing/stable/2023-04-01/types.json
@@ -360,7 +360,7 @@
       "description": "The ID that uniquely identifies an enrollment account.",
       "required": true,
       "type": "string",
-      "pattern": "^[1-9][0-9]*$",
+      "pattern": "^[a-zA-Z\\d-_]{1,128}$",
       "x-ms-parameter-location": "method"
     },
     "departmentName": {
@@ -369,7 +369,7 @@
       "description": "The ID that uniquely identifies the department.",
       "required": true,
       "type": "string",
-      "pattern": "^[1-9][0-9]*$",
+      "pattern": "^[a-zA-Z\\d-_]{1,128}$",
       "x-ms-parameter-location": "method"
     },
     "invoiceName": {