Update recent SDLT purchase schedules and inclusive first-time-buyer cap

changelog.d/2245.fixed.md

@@ -0,0 +1 @@
+Updated recent residential SDLT purchase schedules and applied the inclusive first-time-buyer price maximum, retaining annual sampling and contract-protection limitations.

policyengine_uk/parameters/gov/hmrc/stamp_duty/residential/purchase/additional/rate.yaml

@@ -2,28 +2,36 @@ description: Stamp Duty Land Tax progressive rates for residential property tran
 brackets:
   - rate:
       2016-09-15: 0.03
+      2024-10-31: 0.05
     threshold:
       2016-09-15: 0
   - rate:
       2016-09-15: 0.05
       2020-07-08: null
       2021-03-31: 0.05
+      2022-09-23: null
+      2025-04-01: 0.07
     threshold:
       2016-09-15: 125_000
       2020-07-08: null
       2021-03-31: 125_000
+      2022-09-23: null
+      2025-04-01: 125_000
   - rate:
       2016-09-15: 0.08
+      2024-10-31: 0.10
     threshold:
       2016-09-15: 250_000
       2020-07-08: 500_000
       2021-03-31: 250_000
   - rate:
       2016-09-15: 0.13
+      2024-10-31: 0.15
     threshold:
       2016-09-15: 925_000
   - rate:
       2016-09-15: 0.15
+      2024-10-31: 0.17
     threshold:
       2016-09-15: 1_500_000
 metadata:
@@ -35,3 +43,9 @@ metadata:
       href: https://www.legislation.gov.uk/ukpga/2003/14/schedule/4ZA
     - title: Stamp Duty Land Tax (Temporary Relief) Act 2020
       href: https://www.legislation.gov.uk/ukpga/2020/15/section/1/enacted
+    - title: Stamp Duty Land Tax (Temporary Relief) Act 2023 s. 1(3)
+      href: https://www.legislation.gov.uk/ukpga/2023/2/section/1/enacted
+    - title: Finance Act 2025 s. 50
+      href: https://www.legislation.gov.uk/ukpga/2025/8/section/50/enacted
+    - title: Finance Act 2025 s. 51
+      href: https://www.legislation.gov.uk/ukpga/2025/8/section/51/enacted

policyengine_uk/parameters/gov/hmrc/stamp_duty/residential/purchase/main/first/max.yaml

@@ -1,9 +1,13 @@
 description: Maximum value for a first-property purchase to receive the Stamp Duty relief for first-time buyers. Increasing this value will underestimate the number of claims for FTBR, as the model will not add new claims.
 values:
   2018-03-15: 500_000
+  2022-09-23: 625_000
+  2025-04-01: 500_000
 metadata:
   unit: currency-GBP
   label: Stamp Duty first home value limit
   reference:
     - title: Finance Act 2003 schedule 6ZA(1)(3)
       href: https://www.legislation.gov.uk/ukpga/2003/14/schedule/6ZA/2018-03-15
+    - title: Stamp Duty Land Tax (Temporary Relief) Act 2023 s. 1(5)
+      href: https://www.legislation.gov.uk/ukpga/2023/2/section/1/enacted

policyengine_uk/parameters/gov/hmrc/stamp_duty/residential/purchase/main/first/rate.yaml

@@ -7,6 +7,8 @@ brackets:
     2018-03-15: 0.05
   threshold:
     2018-03-15: 300000
+    2022-09-23: 425000
+    2025-04-01: 300000
 description: Stamp Duty Land Tax progressive rates for residential property transfers.
 metadata:
   economy: false
@@ -16,4 +18,6 @@ metadata:
   reference:
   - href: https://www.legislation.gov.uk/ukpga/2003/14/schedule/6ZA/2018-03-15
     title: Finance Act 2003 schedule 6ZA(4)
+  - href: https://www.legislation.gov.uk/ukpga/2023/2/section/1/enacted
+    title: Stamp Duty Land Tax (Temporary Relief) Act 2023 s. 1(5)
   threshold_unit: currency-GBP

policyengine_uk/parameters/gov/hmrc/stamp_duty/residential/purchase/main/subsequent.yaml

@@ -8,12 +8,16 @@ brackets:
     2015-02-12: 0.02
     2020-07-08: null
     2021-03-31: 0.02
+    2022-09-23: null
+    2025-04-01: 0.02
   threshold:
     2003-07-10: 60000
     2005-04-07: 120000
     2006-07-19: 125000
     2020-07-08: null
     2021-03-31: 125000
+    2022-09-23: null
+    2025-04-01: 125000
 - rate:
     2003-07-10: 0.03
     2015-02-12: 0.05
@@ -50,4 +54,6 @@ metadata:
     title: Finance Act 2003 s. 55
   - href: https://www.legislation.gov.uk/ukpga/2020/15/section/1/enacted
     title: Stamp Duty Land Tax (Temporary Relief) Act 2020
+  - href: https://www.legislation.gov.uk/ukpga/2023/2/section/1/enacted
+    title: Stamp Duty Land Tax (Temporary Relief) Act 2023 s. 1
   threshold_unit: currency-GBP

policyengine_uk/tests/policy/baseline/gov/hmrc/stamp_duty/stamp_duty_land_tax.yaml

@@ -20,13 +20,13 @@
     main_residential_property_purchased_is_first_home: true
   output:
     stamp_duty_land_tax: 7_250
-- name: £500k first-time buyer (just over limit)
+- name: £500,020 first-time buyer (over the £500k limit)
   period: 2022
   input:
-    main_residential_property_purchased: 500_000.01
+    main_residential_property_purchased: 500_020
     main_residential_property_purchased_is_first_home: true
   output:
-    stamp_duty_land_tax: 15_000
+    stamp_duty_land_tax: 15_001
 - name: £500k non-first-time buyer
   period: 2022
   input:

policyengine_uk/tests/policy/baseline/gov/hmrc/stamp_duty/stamp_duty_land_tax_history.yaml

@@ -0,0 +1,150 @@
+# Ordinary, unprotected purchases; annual parameters sample 30 April.
+# Sources: SDLT (Temporary Relief) Act 2023 s1; Finance Act 2025 ss50-51;
+# Finance Act 2003 s55 and Sch6ZA. No transaction-date or contract selector.
+- name: Annual 2022 retains the pre-September standard schedule
+  period: 2022
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 300000
+  output:
+    stamp_duty_land_tax: 5000
+
+- name: Annual 2023 main-home purchase uses temporary standard bands
+  period: 2023
+  absolute_error_margin: 0.01
+  input:
+    main_residence_value: 300000
+    property_purchased: true
+  output:
+    stamp_duty_land_tax: 2500
+    main_residential_property_purchased: 300000
+
+- name: Temporary first-time-buyer maximum is inclusive
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 625000
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 10000
+
+- name: Restored first-time-buyer maximum is inclusive
+  period: 2025
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 500000
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 10000
+
+- name: Annual 2025 additional purchase uses restored bands with five-point surcharge
+  period: 2025
+  absolute_error_margin: 0.01
+  input:
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 30000
+
+- name: Annual 2024 still samples the three-point additional surcharge
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 19500
+
+- name: First-time purchase above temporary maximum loses all relief
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 625020
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 18751
+
+- name: First-time purchase above restored maximum loses all relief
+  period: 2025
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 500020
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 15001
+
+- name: Northern Ireland combines independent temporary main and additional purchases
+  period: 2024
+  absolute_error_margin: 0.01
+  input:
+    region: NORTHERN_IRELAND
+    main_residential_property_purchased: 925000
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 53250
+
+- name: An additional purchase below forty thousand is outside the higher schedule
+  period: 2025
+  input:
+    additional_residential_property_purchased: 39999
+  output:
+    stamp_duty_land_tax: 0
+
+- name: An additional purchase at forty thousand pays the full higher schedule
+  period: 2025
+  absolute_error_margin: 0.01
+  input:
+    additional_residential_property_purchased: 40000
+  output:
+    stamp_duty_land_tax: 2000
+
+- name: Restored purchase schedules persist in later annual simulations
+  period: 2027
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 300000
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 35000
+
+- name: Property stocks without a purchase do not incur SDLT
+  period: 2025
+  input:
+    main_residence_value: 600000
+    property_purchased: false
+    other_residential_property_value: 400000
+  output:
+    stamp_duty_land_tax: 0
+
+- name: Scottish purchases do not incur SDLT
+  period: 2025
+  input:
+    region: SCOTLAND
+    main_residential_property_purchased: 300000
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 0
+
+- name: Welsh purchases do not incur SDLT
+  period: 2025
+  input:
+    region: WALES
+    main_residential_property_purchased: 300000
+    additional_residential_property_purchased: 400000
+  output:
+    stamp_duty_land_tax: 0
+
+- name: Temporary first-time-buyer nil band includes its upper boundary
+  period: 2024
+  input:
+    main_residential_property_purchased: 425000
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 0
+
+- name: Restored first-time-buyer tax starts above three hundred thousand
+  period: 2025
+  absolute_error_margin: 0.01
+  input:
+    main_residential_property_purchased: 300020
+    main_residential_property_purchased_is_first_home: true
+  output:
+    stamp_duty_land_tax: 1

policyengine_uk/tests/test_property_transaction_tax_purchase_properties.py

@@ -121,7 +121,7 @@ def test_main_residence_flag_never_creates_an_additional_purchase(households, ye
     price = out["main_residential_property_purchased"]
     first_home = np.array(
         [h["main_residential_property_purchased_is_first_home"] for h in households]
-    ) & (price < main.first.max)
+    ) & (price <= main.first.max)
     main_rates_tax = np.where(
         first_home, main.first.rate.calc(price), main.subsequent.calc(price)
     )