diff --git a/corporate/views/upgrade.py b/corporate/views/upgrade.py
index 7949b541db..523381f639 100644
--- a/corporate/views/upgrade.py
+++ b/corporate/views/upgrade.py
@@ -4,7 +4,8 @@ from typing import Optional
 from django.conf import settings
 from django.http import HttpRequest, HttpResponse, HttpResponseRedirect
 from django.shortcuts import render
-from pydantic import Json
+from pydantic import AfterValidator, Json
+from typing_extensions import Annotated
 
 from corporate.lib.decorator import (
     authenticated_remote_realm_management_endpoint,
@@ -23,10 +24,9 @@ from corporate.lib.stripe import (
 )
 from corporate.models import CustomerPlan
 from zerver.decorator import require_organization_member, zulip_login_required
-from zerver.lib.request import REQ, has_request_variables
 from zerver.lib.response import json_success
 from zerver.lib.typed_endpoint import typed_endpoint
-from zerver.lib.validator import check_bool, check_int, check_string_in
+from zerver.lib.typed_endpoint_validators import check_string_in
 from zerver.models import UserProfile
 from zilencer.lib.remote_counts import MissingDataError
 
@@ -34,19 +34,26 @@ billing_logger = logging.getLogger("corporate.stripe")
 
 
 @require_organization_member
-@has_request_variables
+@typed_endpoint
 def upgrade(
     request: HttpRequest,
     user: UserProfile,
-    billing_modality: str = REQ(str_validator=check_string_in(VALID_BILLING_MODALITY_VALUES)),
-    schedule: str = REQ(str_validator=check_string_in(VALID_BILLING_SCHEDULE_VALUES)),
-    signed_seat_count: str = REQ(),
-    salt: str = REQ(),
-    license_management: Optional[str] = REQ(
-        default=None, str_validator=check_string_in(VALID_LICENSE_MANAGEMENT_VALUES)
-    ),
-    licenses: Optional[int] = REQ(json_validator=check_int, default=None),
-    tier: int = REQ(default=CustomerPlan.TIER_CLOUD_STANDARD, json_validator=check_int),
+    *,
+    billing_modality: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_MODALITY_VALUES))
+    ],
+    schedule: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_SCHEDULE_VALUES))
+    ],
+    signed_seat_count: str,
+    salt: str,
+    license_management: Optional[
+        Annotated[
+            str, AfterValidator(lambda val: check_string_in(val, VALID_LICENSE_MANAGEMENT_VALUES))
+        ]
+    ] = None,
+    licenses: Optional[Json[int]] = None,
+    tier: Json[int] = CustomerPlan.TIER_CLOUD_STANDARD,
 ) -> HttpResponse:
     try:
         upgrade_request = UpgradeRequest(
@@ -84,20 +91,27 @@ def upgrade(
 
 
 @authenticated_remote_realm_management_endpoint
-@has_request_variables
+@typed_endpoint
 def remote_realm_upgrade(
     request: HttpRequest,
     billing_session: RemoteRealmBillingSession,
-    billing_modality: str = REQ(str_validator=check_string_in(VALID_BILLING_MODALITY_VALUES)),
-    schedule: str = REQ(str_validator=check_string_in(VALID_BILLING_SCHEDULE_VALUES)),
-    signed_seat_count: str = REQ(),
-    salt: str = REQ(),
-    license_management: Optional[str] = REQ(
-        default=None, str_validator=check_string_in(VALID_LICENSE_MANAGEMENT_VALUES)
-    ),
-    licenses: Optional[int] = REQ(json_validator=check_int, default=None),
-    remote_server_plan_start_date: Optional[str] = REQ(default=None),
-    tier: int = REQ(default=CustomerPlan.TIER_SELF_HOSTED_BUSINESS, json_validator=check_int),
+    *,
+    billing_modality: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_MODALITY_VALUES))
+    ],
+    schedule: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_SCHEDULE_VALUES))
+    ],
+    signed_seat_count: str,
+    salt: str,
+    license_management: Optional[
+        Annotated[
+            str, AfterValidator(lambda val: check_string_in(val, VALID_LICENSE_MANAGEMENT_VALUES))
+        ]
+    ] = None,
+    licenses: Optional[Json[int]] = None,
+    remote_server_plan_start_date: Optional[str] = None,
+    tier: Json[int] = CustomerPlan.TIER_SELF_HOSTED_BUSINESS,
 ) -> HttpResponse:
     try:
         upgrade_request = UpgradeRequest(
@@ -133,20 +147,27 @@ def remote_realm_upgrade(
 
 
 @authenticated_remote_server_management_endpoint
-@has_request_variables
+@typed_endpoint
 def remote_server_upgrade(
     request: HttpRequest,
     billing_session: RemoteServerBillingSession,
-    billing_modality: str = REQ(str_validator=check_string_in(VALID_BILLING_MODALITY_VALUES)),
-    schedule: str = REQ(str_validator=check_string_in(VALID_BILLING_SCHEDULE_VALUES)),
-    signed_seat_count: str = REQ(),
-    salt: str = REQ(),
-    license_management: Optional[str] = REQ(
-        default=None, str_validator=check_string_in(VALID_LICENSE_MANAGEMENT_VALUES)
-    ),
-    licenses: Optional[int] = REQ(json_validator=check_int, default=None),
-    remote_server_plan_start_date: Optional[str] = REQ(default=None),
-    tier: int = REQ(default=CustomerPlan.TIER_SELF_HOSTED_BUSINESS, json_validator=check_int),
+    *,
+    billing_modality: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_MODALITY_VALUES))
+    ],
+    schedule: Annotated[
+        str, AfterValidator(lambda val: check_string_in(val, VALID_BILLING_SCHEDULE_VALUES))
+    ],
+    signed_seat_count: str,
+    salt: str,
+    license_management: Optional[
+        Annotated[
+            str, AfterValidator(lambda val: check_string_in(val, VALID_LICENSE_MANAGEMENT_VALUES))
+        ]
+    ] = None,
+    licenses: Optional[Json[int]] = None,
+    remote_server_plan_start_date: Optional[str] = None,
+    tier: Json[int] = CustomerPlan.TIER_SELF_HOSTED_BUSINESS,
 ) -> HttpResponse:
     try:
         upgrade_request = UpgradeRequest(
@@ -182,12 +203,13 @@ def remote_server_upgrade(
 
 
 @zulip_login_required
-@has_request_variables
+@typed_endpoint
 def upgrade_page(
     request: HttpRequest,
-    manual_license_management: bool = REQ(default=False, json_validator=check_bool),
-    tier: int = REQ(default=CustomerPlan.TIER_CLOUD_STANDARD, json_validator=check_int),
-    setup_payment_by_invoice: bool = REQ(default=False, json_validator=check_bool),
+    *,
+    manual_license_management: Json[bool] = False,
+    tier: Json[int] = CustomerPlan.TIER_CLOUD_STANDARD,
+    setup_payment_by_invoice: Json[bool] = False,
 ) -> HttpResponse:
     user = request.user
     assert user.is_authenticated
diff --git a/zerver/lib/typed_endpoint_validators.py b/zerver/lib/typed_endpoint_validators.py
index efe3f1c585..8b3dd4589c 100644
--- a/zerver/lib/typed_endpoint_validators.py
+++ b/zerver/lib/typed_endpoint_validators.py
@@ -21,6 +21,12 @@ def check_string_fixed_length(string: str, length: int) -> Optional[str]:
     return string
 
 
+def check_string_in(val: str, possible_values: List[str]) -> str:
+    if val not in possible_values:
+        raise ValueError(_("Not in the list of possible values"))
+    return val
+
+
 def check_int_in(val: int, possible_values: List[int]) -> int:
     if val not in possible_values:
         raise ValueError(_("Not in the list of possible values"))