diff --git a/fusion_portal/controllers/portal_main.py b/fusion_portal/controllers/portal_main.py
index b5f65b51..0563e099 100644
--- a/fusion_portal/controllers/portal_main.py
+++ b/fusion_portal/controllers/portal_main.py
@@ -2493,7 +2493,14 @@ class AuthorizerPortal(CustomerPortal):
             assessment_type = post.get('assessment_type')
             if not assessment_type:
                 return {'success': False, 'error': 'Assessment type is required'}
-            
+
+            # Funding source drives the downstream sale-order workflow; coerce
+            # anything unexpected to private pay (mirrors /book-assessment).
+            _funding_keys = dict(Assessment._fields['x_fc_funding_source'].selection)
+            funding_source = post.get('funding_source') or 'direct_private'
+            if funding_source not in _funding_keys:
+                funding_source = 'direct_private'
+
             # Build assessment values
             vals = {
                 'assessment_type': assessment_type,
@@ -2507,7 +2514,7 @@ class AuthorizerPortal(CustomerPortal):
                 'client_address_postal': post.get('client_address_postal', '').strip(),
                 'client_phone': post.get('client_phone', '').strip(),
                 'client_email': post.get('client_email', '').strip(),
-                'x_fc_funding_source': post.get('funding_source') or 'direct_private',
+                'x_fc_funding_source': funding_source,
                 'notes': post.get('notes', '').strip(),
             }