diff --git a/atst/forms/financial.py b/atst/forms/financial.py
index e989d822..93d08258 100644
--- a/atst/forms/financial.py
+++ b/atst/forms/financial.py
@@ -1,7 +1,7 @@
 import re
 from wtforms.fields.html5 import EmailField
 from wtforms.fields import StringField
-from wtforms.validators import Required, Email, Regexp, ValidationError
+from wtforms.validators import Required, Email, Regexp
 
 from atst.domain.exceptions import NotFoundError
 from atst.domain.pe_numbers import PENumbers
@@ -58,6 +58,16 @@ def validate_pe_id(field, existing_request):
     return True
 
 
+def validate_task_order_number(field):
+    try:
+        TaskOrders.get(field.data)
+    except NotFoundError:
+        field.errors += ("Task Order number not found",)
+        return False
+
+    return True
+
+
 class BaseFinancialForm(ValidatedForm):
     def reset(self):
         """
@@ -119,11 +129,10 @@ class BaseFinancialForm(ValidatedForm):
 
 
 class FinancialForm(BaseFinancialForm):
-    def validate_task_order_number(form, field):
-        try:
-            TaskOrders.get(field.data)
-        except NotFoundError:
-            raise ValidationError("Task Order number not found")
+    def perform_extra_validation(self, existing_request):
+        previous_valid = super().perform_extra_validation(existing_request)
+        task_order_valid = validate_task_order_number(self.task_order_number)
+        return previous_valid and task_order_valid
 
     @property
     def is_missing_task_order_number(self):
diff --git a/tests/forms/test_financial.py b/tests/forms/test_financial.py
index 871c7c19..3f0d5e91 100644
--- a/tests/forms/test_financial.py
+++ b/tests/forms/test_financial.py
@@ -71,13 +71,14 @@ def test_ba_code_validation(input_, expected):
 
 def test_task_order_number_validation(monkeypatch):
     monkeypatch.setattr("atst.domain.task_orders.TaskOrders._client", lambda: MockEDAClient())
+    monkeypatch.setattr("atst.forms.financial.validate_pe_id", lambda *args: True)
     form_invalid = FinancialForm(data={"task_order_number": "1234"})
-    form_invalid.validate()
+    form_invalid.perform_extra_validation({})
 
     assert "task_order_number" in form_invalid.errors
 
     form_valid = FinancialForm(data={"task_order_number": MockEDAClient.MOCK_CONTRACT_NUMBER}, eda_client=MockEDAClient())
-    form_valid.validate()
+    form_valid.perform_extra_validation({})
 
     assert "task_order_number" not in form_valid.errors