diff --git a/domain/sap10_calculator/rdsap/cert_to_inputs.py b/domain/sap10_calculator/rdsap/cert_to_inputs.py
index efc2d20a..c7218cd8 100644
--- a/domain/sap10_calculator/rdsap/cert_to_inputs.py
+++ b/domain/sap10_calculator/rdsap/cert_to_inputs.py
@@ -92,7 +92,6 @@ from domain.sap10_calculator.tables.table_12 import (
     co2_factor_kg_per_kwh,
     pe_monthly_factors_kwh_per_kwh,
     primary_energy_factor,
-    unit_price_p_per_kwh,
 )
 from domain.sap10_calculator.tables.table_12a import (
     OtherUse,
@@ -471,14 +470,35 @@ _SPEC_E7_ELIGIBLE_MAIN_CODES: Final[frozenset[int]] = frozenset(
 )
 
 
-SAP_10_2_SPEC_PRICES: Final[PriceTable] = PriceTable(
-    unit_price_p_per_kwh=unit_price_p_per_kwh,
-    e7_low_rate_p_per_kwh=9.40,
-    standard_electricity_p_per_kwh=16.49,
+# RdSAP 10 Table 32 (PDF page 95) — the canonical SAP-rating price set per
+# the RdSAP 10 §19.1 spec text:
+#
+#   "The SAP rating for RdSAP 10 is to be calculated using Table 32 prices
+#    (not Table 12) for section 10a and 10b."
+#
+# Table 32 mains gas = 3.48 p/kWh (vs SAP 10.2 Table 12 = 3.64);
+# 7-hour low = 5.50 p/kWh (vs Table 12 = 9.40);
+# standard electricity = 13.19 p/kWh (vs Table 12 = 16.49).
+#
+# Wired into `cert_to_inputs` as the default PriceTable per ADR-0010
+# §10a amendment (2026-05-21). Off-peak fallback scalars
+# (`hot_water_fuel_cost_gbp_per_kwh` etc.) read `unit_price_p_per_kwh`
+# directly so this is where the cohort-wide tariff lands.
+RDSAP_10_TABLE_32_PRICES: Final[PriceTable] = PriceTable(
+    unit_price_p_per_kwh=table_32_unit_price_p_per_kwh,
+    e7_low_rate_p_per_kwh=5.50,  # Table 32 code 31 (7-hour low)
+    standard_electricity_p_per_kwh=13.19,  # Table 32 code 30
     e7_eligible_main_codes=_SPEC_E7_ELIGIBLE_MAIN_CODES,
 )
 
 
+# Legacy alias retained so existing imports keep working. Per ADR-0010
+# §10a amendment the SAP rating uses Table 32 prices, NOT SAP 10.2
+# Table 12 — the name is preserved for back-compat; both constants point
+# at the same Table 32 PriceTable instance.
+SAP_10_2_SPEC_PRICES: Final[PriceTable] = RDSAP_10_TABLE_32_PRICES
+
+
 # SAP 10.2 Table 4e (page 171) main_heating_control codes → control type
 # (1/2/3 per Table 9 "Heating control type" column). Type drives the
 # elsewhere-zone off-hours pattern in Table 9: types 1+2 use (7, 8),
diff --git a/domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py b/domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py
index 21aa00ef..97c0cc83 100644
--- a/domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py
+++ b/domain/sap10_calculator/rdsap/tests/test_cert_to_inputs.py
@@ -751,12 +751,14 @@ def test_gas_heating_with_electric_immersion_charges_hw_at_electricity_rate() ->
 
     # Assert — gas main → space heating at gas rate; HW switches to electric
     # rate when water_heating_fuel is electric; lighting/pumps always electric.
-    assert inputs_gas.space_heating_fuel_cost_gbp_per_kwh == 0.0364
-    assert inputs_gas.hot_water_fuel_cost_gbp_per_kwh == 0.0364
-    assert inputs_gas.other_fuel_cost_gbp_per_kwh == 0.1649
-    assert inputs_hw.space_heating_fuel_cost_gbp_per_kwh == 0.0364
-    assert inputs_hw.hot_water_fuel_cost_gbp_per_kwh == 0.1649
-    assert inputs_hw.other_fuel_cost_gbp_per_kwh == 0.1649
+    # Prices are RdSAP 10 Table 32 (PDF p.95) per the ADR-0010 §10a amendment:
+    #   mains gas = 3.48 p/kWh; standard electricity (code 30) = 13.19 p/kWh.
+    assert inputs_gas.space_heating_fuel_cost_gbp_per_kwh == 0.0348
+    assert inputs_gas.hot_water_fuel_cost_gbp_per_kwh == 0.0348
+    assert inputs_gas.other_fuel_cost_gbp_per_kwh == 0.1319
+    assert inputs_hw.space_heating_fuel_cost_gbp_per_kwh == 0.0348
+    assert inputs_hw.hot_water_fuel_cost_gbp_per_kwh == 0.1319
+    assert inputs_hw.other_fuel_cost_gbp_per_kwh == 0.1319
 
 
 def test_main_heating_control_code_maps_to_sap_control_type() -> None:
@@ -812,7 +814,8 @@ def test_off_peak_meter_routes_electric_costs_to_low_rate() -> None:
     # now apply Table 12a Grid 2 ALL_OTHER_USES + SEVEN_HOUR = 0.90
     # high → blended 0.90 * 15.29 + 0.10 * 5.50 = 14.311 p/kWh per
     # Slice S0380.61 (was 16.49 under the pre-Table-12a empirical
-    # override).
+    # override). RdSAP 10 Table 32 (PDF p.95) per ADR-0010 §10a
+    # amendment: 7-hour low (code 31) = 5.50 p/kWh.
     epc = make_minimal_sap10_epc(
         total_floor_area_m2=_TYPICAL_TFA_M2,
         habitable_rooms_count=3,
@@ -846,8 +849,8 @@ def test_off_peak_meter_routes_electric_costs_to_low_rate() -> None:
     inputs = cert_to_inputs(epc)
 
     # Assert
-    assert inputs.space_heating_fuel_cost_gbp_per_kwh == 0.094
-    assert inputs.hot_water_fuel_cost_gbp_per_kwh == 0.094
+    assert inputs.space_heating_fuel_cost_gbp_per_kwh == 0.055
+    assert inputs.hot_water_fuel_cost_gbp_per_kwh == 0.055
     assert abs(inputs.other_fuel_cost_gbp_per_kwh - 0.14311) < 1e-5
 
 
@@ -1266,9 +1269,11 @@ def test_standard_meter_keeps_electric_costs_on_standard_rate() -> None:
     inputs = cert_to_inputs(epc)
 
     # Assert — no off-peak routing; all-electric dwelling pays standard rates.
-    assert inputs.space_heating_fuel_cost_gbp_per_kwh == 0.1649
-    assert inputs.hot_water_fuel_cost_gbp_per_kwh == 0.1649
-    assert inputs.other_fuel_cost_gbp_per_kwh == 0.1649
+    # RdSAP 10 Table 32 (PDF p.95) standard electricity (code 30) = 13.19
+    # p/kWh per ADR-0010 §10a amendment.
+    assert inputs.space_heating_fuel_cost_gbp_per_kwh == 0.1319
+    assert inputs.hot_water_fuel_cost_gbp_per_kwh == 0.1319
+    assert inputs.other_fuel_cost_gbp_per_kwh == 0.1319
 
 
 def test_mid_floor_flat_dwelling_type_zeroes_floor_and_roof_heat_transmission() -> None:
@@ -2083,3 +2088,45 @@ def test_air_source_heat_pump_main_heating_zeroes_table_3a_combi_loss_per_sap_4_
             f"month {month_idx}: combi loss {value!r} should be 0 for "
             f"non-combi main heating per SAP 10.2 §4 line 7702"
         )
+
+
+def test_rdsap_10_table_32_prices_charge_mains_gas_hot_water_at_3p48_per_kwh() -> None:
+    """RdSAP 10 Specification §19.1 (PDF page 80-81) — the §10a fuel-cost
+    block uses RdSAP 10 Table 32 (PDF page 95) prices, NOT SAP 10.2
+    Table 12 (PDF page 189):
+
+        "The SAP rating for RdSAP 10 is to be calculated using Table 32
+         prices (not Table 12) for section 10a and 10b."
+
+    Table 32 row "Mains gas" = 3.48 p/kWh; the SAP 10.2 Table 12 row is
+    3.64 p/kWh. Per ADR-0010 amendment (2026-05-21), the §10a orchestrator
+    already targets Table 32. This pin closes the residual gap on the
+    legacy off-peak scalar fallback `inputs.hot_water_fuel_cost_gbp_per_
+    kwh` so it ALSO reads Table 32 — the cohort's `prices` PriceTable
+    callable must return 3.48 for mains-gas DHW.
+
+    Cert 000565 lodges Dual meter (Tariff.TEN_HOUR) + gas-combi DHW via
+    WHC 914 (mains gas Table 32 code 1). It hits the off-peak fallback
+    branch in the calculator (`fuel_cost is _ZERO_FUEL_COST_FOR_OFF_PEAK`)
+    so this scalar IS the consumed cost — the +£6 over-count on the
+    cohort handover trace is exactly the £0.16 p/kWh × 3755 HW kWh
+    delta. Closes cert 000565 sap_score 28 → 29 EXACT at the 28.5
+    rounding boundary.
+    """
+    # Arrange — mapper-driven cohort fixture (Summary_000565 → cert_to_
+    # inputs), Dual meter / mains gas DHW.
+    from domain.sap10_calculator.worksheet.tests import (
+        _elmhurst_worksheet_000565 as _w000565,
+    )
+    epc = _w000565.build_epc()
+
+    # Act
+    inputs = cert_to_inputs(epc)
+
+    # Assert — HW £/kWh equals Table 32 mains gas (3.48 p/kWh = 0.0348
+    # £/kWh), NOT Table 12 (3.64 p/kWh = 0.0364 £/kWh).
+    assert abs(inputs.hot_water_fuel_cost_gbp_per_kwh - 0.0348) <= 1e-6, (
+        f"hot_water_fuel_cost_gbp_per_kwh = "
+        f"{inputs.hot_water_fuel_cost_gbp_per_kwh!r}, expected 0.0348 per "
+        f"RdSAP 10 Table 32 mains gas (§19.1 amendment, ADR-0010)"
+    )