diff --git a/resalloc_ibm_cloud/argparsers.py b/resalloc_ibm_cloud/argparsers.py
index f950676..e3aaf0c 100644
--- a/resalloc_ibm_cloud/argparsers.py
+++ b/resalloc_ibm_cloud/argparsers.py
@@ -14,8 +14,8 @@ def default_arg_parser():
         "--token-file", help="Path to IBM cloud token file", required=True
     )
     parser.add_argument(
-        "--service-url",
-        help="SERVICE URL e.g. https://jp-tok.iaas.cloud.ibm.com/v1",
+        "--zone",
+        help="default IBM Cloud zone. e.g. jp-tok, us-east, us-west, ...",
         required=True,
     )
     return parser
diff --git a/resalloc_ibm_cloud/helpers.py b/resalloc_ibm_cloud/helpers.py
index 027fa3c..336c65c 100644
--- a/resalloc_ibm_cloud/helpers.py
+++ b/resalloc_ibm_cloud/helpers.py
@@ -12,5 +12,5 @@ def get_service(cmd: str, opts: Namespace):
     authenticator = IAMAuthenticator(token)
     now = datetime.datetime.now()
     service = VpcV1(now.strftime("%Y-%m-%d"), authenticator=authenticator)
-    service.set_service_url(opts.service_url)
+    service.set_service_url(f"https://{opts.zone}.iaas.cloud.ibm.com/v1")
     return service
diff --git a/resalloc_ibm_cloud/ibm_cloud_vm.py b/resalloc_ibm_cloud/ibm_cloud_vm.py
index dcc977f..9614154 100755
--- a/resalloc_ibm_cloud/ibm_cloud_vm.py
+++ b/resalloc_ibm_cloud/ibm_cloud_vm.py
@@ -65,9 +65,7 @@ def allocate_and_assign_ip(service, opts):
     Allocate and assign a Floating IP to an existing machine in one call.
     """
 
-    service_url = (
-        opts.service_url[:-1] if opts.service_url[-1] == "/" else opts.service_url
-    )
+    service_url = f"https://{opts.zone}.iaas.cloud.ibm.com/v1"
     url = service_url + "/floating_ips"
     headers = {
         "Accept": "application/json",
@@ -164,7 +162,7 @@ def create_instance(service, instance_name, opts):
             ],
         },
         "zone": {
-            "name": opts.zone,
+            "name": urlparse(opts.se),
         },
         "volume_attachments": [
             {