diff --git a/backend/documents_parser/tests/test_pashub_sap_accuracy.py b/backend/documents_parser/tests/test_pashub_sap_accuracy.py
index bac2bafd0..25d2d8009 100644
--- a/backend/documents_parser/tests/test_pashub_sap_accuracy.py
+++ b/backend/documents_parser/tests/test_pashub_sap_accuracy.py
@@ -321,3 +321,26 @@ def test_pashub_sap_accuracy_aggregate(capsys: pytest.CaptureFixture[str]) -> No
     assert sap_mae <= _MAX_SAP_MAE, (
         f"SAP MAE {sap_mae:.3f} exceeded ceiling {_MAX_SAP_MAE}"
     )
+
+
+@pytest.mark.skipif(not _FIXTURES, reason="no pashub_accuracy fixtures/manifest")
+def test_walsden_pins_to_pashub_resurvey_sap_64() -> None:
+    """13 Walsden Street (deal 499630239947) has TWO distinct gov-EPC assessments
+    for the same UPRN: the PAS Hub site-note re-survey we parse (inspected
+    26 May 2026, accredited SAP **64**, band D, backed by `rd_sap_site_note`
+    files) and a SEPARATE later lodged cert (24 Jun 2026, SAP 68, registered, no
+    site-note). The portfolio-838 baseline latched onto the 24-Jun SAP-68 cert,
+    but our engine models the survey it was GIVEN and reproduces that survey's own
+    accredited 64 (~64.19). Confirmed against pashub (Khalim) and corroborated by
+    the manifest `pre_sap` D64 + hubspot D64; see the 2026-07-15e provenance
+    investigation in the campaign memory. The manifest is correctly 64, but the
+    fixture-builder can revert manifest values to a colliding DB row — so this pins
+    64 explicitly. Do NOT "correct" this target to 68: that is a different
+    assessment with no site-note backing, and 13 Walsden is a known
+    re-survey-diverges outlier, not an engine under-rate."""
+    outcome = _evaluate("499630239947")
+    assert outcome.sap_continuous is not None
+    assert abs(outcome.sap_continuous - 64) < 0.5, (
+        f"13 Walsden SAP {outcome.sap_continuous:.2f} diverged from the PAS Hub "
+        "re-survey's own accredited 64 (NOT the colliding 24-Jun cert's 68)"
+    )