Correct programme agencies and national coverage

changelog.d/2696.fixed.md

@@ -0,0 +1 @@
+The programme registry identifies the correct responsible bodies and nations for Scottish income tax, tax credits, the Energy Price Guarantee, Council Tax, Council Tax Reduction and Winter Fuel Payment.

policyengine_uk/programs.yaml

@@ -375,13 +375,13 @@ programs:
     name: Tax credits
     full_name: Tax Credits (Working Tax Credit and Child Tax Credit)
     category: Benefits
-    agency: DWP
+    agency: HMRC
     status: complete
     coverage: UK
     variable: tax_credits
     parameter_prefix: gov.dwp.tax_credits
     verified_start_year: 2022
-    notes: Legacy benefit being replaced by Universal Credit
+    notes: HMRC administered Working Tax Credit and Child Tax Credit until they ended on 5 April 2025
 
   - id: sda
     name: SDA
@@ -400,11 +400,11 @@ programs:
     category: Benefits
     agency: DWP
     status: complete
-    coverage: UK
+    coverage: England, Wales and Northern Ireland
     variable: winter_fuel_payment
     parameter_prefix: gov.dwp.winter_fuel_payment
     verified_start_year: 2022
-    notes: Great Britain to winter 2023-24, then England and Wales; Northern Ireland's mirror scheme uses the same parameters. From winter 2025-26 paid to everyone of pensionable age and recovered by the winter fuel payment charge (income tax)
+    notes: Great Britain to winter 2023-24, then England and Wales; Northern Ireland's mirror scheme uses the same parameters. The Scottish Government replaced it with Pension Age Winter Heating Payment from winter 2024-25. From winter 2025-26 HMRC recovers payments from higher-income recipients through the winter fuel payment charge (income tax)
 
   - id: ssmg
     name: Sure Start Maternity Grant
@@ -572,7 +572,7 @@ programs:
     category: Taxes
     agency: Local
     status: complete
-    coverage: UK
+    coverage: Great Britain
     variable: council_tax
     verified_start_year: 2022
 
@@ -582,7 +582,7 @@ programs:
     category: Benefits
     agency: Local
     status: partial
-    coverage: UK
+    coverage: Great Britain
     variable: council_tax_reduction
     parameter_prefix: gov.local_authorities
     verified_start_year: 2013
@@ -606,7 +606,7 @@ programs:
     name: Energy Price Guarantee
     full_name: Energy Price Guarantee
     category: Benefits
-    agency: Ofgem
+    agency: DESNZ
     status: partial
     coverage: UK
     parameter_prefix: gov.ofgem
@@ -635,7 +635,7 @@ programs:
     name: Scottish income tax
     full_name: Scottish Income Tax Rates
     category: Taxes
-    agency: Revenue Scotland
+    agency: HMRC
     status: complete
     coverage: Scotland
     verified_start_year: 2019

policyengine_uk/tests/test_program_registry.py

@@ -2,6 +2,7 @@
 
 import pytest
 import yaml
+from hypothesis import given, settings, strategies as st
 from policyengine_core.parameters import ParameterNode
 
 from policyengine_uk import CountryTaxBenefitSystem
@@ -54,3 +55,59 @@ def test_benefit_cap_does_not_advertise_unrelated_parameters(tax_benefit_system)
         advertised.get_child("non_single.outside_london")
         is benefit_cap.non_single.outside_london
     )
+
+
+@pytest.mark.parametrize(
+    "program_id, field, expected",
+    [
+        ("scottish_income_tax", "agency", "HMRC"),
+        ("tax_credits", "agency", "HMRC"),
+        ("energy_price_guarantee", "agency", "DESNZ"),
+        ("council_tax", "coverage", "Great Britain"),
+        ("council_tax_reduction", "coverage", "Great Britain"),
+        (
+            "winter_fuel_payment",
+            "coverage",
+            "England, Wales and Northern Ireland",
+        ),
+    ],
+    ids=lambda value: value,
+)
+def test_program_agency_and_coverage(program_id, field, expected):
+    """The registry identifies the administering body and nations (#2696)."""
+    programs = [p for p in PROGRAMS if p["id"] == program_id]
+    assert len(programs) == 1
+    assert programs[0][field] == expected
+
+
+@pytest.mark.parametrize(
+    "program_id, date",
+    [
+        ("tax_credits", "5 April 2025"),
+        ("winter_fuel_payment", "from winter 2024-25"),
+    ],
+    ids=lambda value: value,
+)
+def test_program_notes_state_when_the_scheme_changed(program_id, date):
+    """The notes keep each programme's sourced end or replacement date (#2696)."""
+    programs = [p for p in PROGRAMS if p["id"] == program_id]
+    assert len(programs) == 1
+    assert date in programs[0]["notes"]
+
+
+@settings(max_examples=len(PROGRAMS), database=None, derandomize=True)
+@given(program_id=st.sampled_from(tuple(p["id"] for p in PROGRAMS)))
+def test_program_metadata_survives_loading(tax_benefit_system, program_id):
+    """Core exposes every program's agency and coverage strings unchanged."""
+    registry_program = next(p for p in PROGRAMS if p["id"] == program_id)
+    loaded_programs = [
+        p
+        for p in tax_benefit_system.modelled_policies["programs"]
+        if p["id"] == program_id
+    ]
+    assert len(loaded_programs) == 1
+    for field in ("agency", "coverage"):
+        value = loaded_programs[0][field]
+        assert isinstance(value, str)
+        assert value
+        assert value == registry_program[field]