PolicyEngine/policyengine-uk

An open-source static tax-benefit microsimulation model for the UK.

Stars: 50
Forks: 33
Open beginner issues: 4
Indexed issues: 157
Avg merge: 20h 58m
Merged PRs (30d): 14

Dominant language: Python
License: AGPL-3.0
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: No code of conduct
Beginner labels: No beginner labels indexed

Beginner friendly Everything

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157 open issues indexed

Four more variables declare uprating but are missing from uprating_indices.yaml Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

PolicyEngine/policyengine-uk#1862 · Opened Sep 18, 2026
Council tax integration: Nuffield Workstream 2 deliverable tracker Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1854 · 2 comments · Opened Sep 15, 2026
Scottish Two Child Limit Payment is in effect from 2025-04-06 but the scheme was never enacted Open

bug parameters

Difficulty 2/5 1-3 hours Newbie friendliness 85/100

PolicyEngine/policyengine-uk#1852 · Opened Sep 8, 2026
UKSingleYearDataset silently ignores fiscal_year with file_path, and defaults it to a hardcoded 2025 Open

PolicyEngine/policyengine-uk#1845 · 1 assignee · Opened Sep 3, 2026
Extensive-margin participation: wage imputation double-divides by 52, and childcare cost when working is not imputed Open

Difficulty 5/5 Over a week Newbie friendliness 45/100

PolicyEngine/policyengine-uk#1839 · Opened Aug 31, 2026
Pre-existing defects in dynamics/participation.py that surface when the participation model is enabled Open

Difficulty 5/5 Over a week Newbie friendliness 38/100

PolicyEngine/policyengine-uk#1836 · Opened Aug 28, 2026
Imputed potential earnings are too coarse to exercise the OBR participation elasticity gradient Open

Difficulty 5/5 Over a week Newbie friendliness 45/100

PolicyEngine/policyengine-uk#1835 · Opened Aug 28, 2026
Dividend band thresholds lag the main-rate bands: HRT £37,700 from 2021 and ART £125,140 from 2023 only applied to dividends from April 2026 Open

Difficulty 2/5 1-3 hours Newbie friendliness 84/100

PolicyEngine/policyengine-uk#1822 · Opened Aug 17, 2026
Benefit cap applies to 2x too many households (5.3% of UC vs 1.6% administrative) Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1818 · 4 comments · Opened Aug 12, 2026
CI HUGGING_FACE_TOKEN failing with 401 on private dataset downloads Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1816 · 5 comments · Opened Aug 5, 2026
Housing Benefit (pensioner) take-up assumed 100%; DWP measures ~85% Open

Difficulty 4/5 3-5 days Newbie friendliness 55/100

PolicyEngine/policyengine-uk#1813 · Opened Aug 2, 2026
Ensure each year has >10k effective sample sizes Open

PolicyEngine/policyengine-uk#1812 · 1 assignee · Opened Jul 27, 2026
Ensure years are directly comparable Open

PolicyEngine/policyengine-uk#1811 · 1 assignee · Opened Jul 27, 2026
Mid-year parameter changes are dropped by fiscal year conversion Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1807 · Opened Jul 25, 2026
Model income shifting between capital gains and income Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1805 · Opened Jul 25, 2026
Structural-trigger parameters are sampled at a fixed instant, so reforms gating structural changes can silently fail to activate Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

PolicyEngine/policyengine-uk#1800 · Opened Jul 16, 2026
Starting rate for savings: band is not tapered until other income exceeds £30,140; should taper from the Personal Allowance (£12,570) Open

Difficulty 3/5 1-2 days Newbie friendliness 64/100

PolicyEngine/policyengine-uk#1799 · Opened Jul 13, 2026
Welsh LTT residential rates stale (missing 10 October 2022 main and 11 December 2024 higher-rate changes) Open

Difficulty 2/5 1-3 hours Newbie friendliness 75/100

PolicyEngine/policyengine-uk#1796 · Opened Jul 7, 2026
Scottish LBTT Additional Dwelling Supplement stale at 6% (should be 8% from 5 December 2024) Open

Difficulty 1/5 Under an hour Newbie friendliness 91/100

PolicyEngine/policyengine-uk#1795 · Opened Jul 7, 2026
Housing Benefit earnings disregard stacks the base disregard on top of the worker disregard (over-disregard vs SI 2006/213 Sch 4) Open

Difficulty 4/5 3-5 days Newbie friendliness 52/100

PolicyEngine/policyengine-uk#1794 · Opened Jul 6, 2026
Reported/category benefit inputs bypass statutory minimum-age eligibility (Carer's Allowance, Carer Support Payment, child DLA mobility) Open

Difficulty 4/5 3-5 days Newbie friendliness 52/100

PolicyEngine/policyengine-uk#1793 · Opened Jul 5, 2026
Add visible keyboard shortcut hints to the search dialog Open

Difficulty 3/5 1-2 days Newbie friendliness 62/100

PolicyEngine/policyengine-uk#1792 · Opened Jun 30, 2026
Roadmap: complete, interaction-aware UK tax–benefit coverage (2000-onward) Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1775 · 1 comment · Opened Jun 8, 2026
EFRS student_loan_repayments input overrides modelled repayment formula Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1764 · Opened Jun 5, 2026
Model Winter Fuel Payment high-income recovery separately from entitlement Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

PolicyEngine/policyengine-uk#1760 · Opened Jun 5, 2026
WTC 30-hour element is CPI-uprated instead of using the 2024-25 rate Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

PolicyEngine/policyengine-uk#1759 · Opened Jun 5, 2026
Legacy capital tariff income omits prescribed-accommodation branch Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

PolicyEngine/policyengine-uk#1758 · Opened Jun 5, 2026
Update 2026-27 Pension Credit additional amounts Open

Difficulty 3/5 1-2 days Newbie friendliness 64/100

PolicyEngine/policyengine-uk#1742 · Opened May 30, 2026
Update 2026-27 Universal Credit Regulation 36 amounts Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

PolicyEngine/policyengine-uk#1741 · 1 comment · Opened May 30, 2026
Update 2026-27 Pension Credit guarantee rates Open

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

PolicyEngine/policyengine-uk#1740 · Opened May 30, 2026
Update 2026-27 Child Benefit rates Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

PolicyEngine/policyengine-uk#1739 · Opened May 30, 2026
Define PolicyEngine-UK switch and rollback path for mp-30k-uk Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1692 · Opened May 26, 2026
Add rules-based formula for council_tax_benefit Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1669 · Opened May 11, 2026
Audit: UK childcare programme coverage — devolved gaps and structural cleanups Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1644 · Opened Apr 21, 2026
State pension undershoot: -£12bn vs OBR, ASP/Protected Payment under-captured Open

bug

Difficulty 5/5 Over a week Newbie friendliness 38/100

PolicyEngine/policyengine-uk#1632 · Opened Apr 18, 2026
Household-impact tests return 0 for expected-positive tax/benefit values on 2.88.0 Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

PolicyEngine/policyengine-uk#1628 · Opened Apr 17, 2026
Align UK model/data pipeline with US patterns: reported-anchoring, second-stage imputation, and downstream bugs Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1621 · Opened Apr 17, 2026
Add legislative references Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

PolicyEngine/policyengine-uk#1458 · 1 comment · Opened Dec 18, 2025
Use April dates for uprating indices to align with UK fiscal year Open

Difficulty 4/5 3-5 days Newbie friendliness 38/100

PolicyEngine/policyengine-uk#1437 · 1 comment · Opened Dec 3, 2025
Explore on-the-fly fiscal year parameter conversion Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1436 · Opened Dec 3, 2025
Validate PolicyEngine child poverty estimates against RF/OBR benchmarks Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1398 · Opened Nov 27, 2025
Analyze effective take-up rates across all benefit programs Open

Difficulty 5/5 Over a week Newbie friendliness 30/100

PolicyEngine/policyengine-uk#1354 · 5 comments · Opened Oct 5, 2025
Add firm analysis files Open

PolicyEngine/policyengine-uk#1333 · 1 assignee · Opened Aug 31, 2025
Add firm-level VAT logic with new Firm entity Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1320 · 1 comment · Opened Aug 19, 2025
Ubuntu is returning different results from macos Open

PolicyEngine/policyengine-uk#1209 · 1 comment · 1 assignee · Opened Jul 11, 2025
Add RF methodology for earnings growth Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

PolicyEngine/policyengine-uk#1179 · Opened Jul 9, 2025
Model indirect tax effects of individual tax reforms Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1114 · Opened Apr 25, 2025
PIP point system Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1069 · Opened Mar 18, 2025
Regional childcare programs Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#1008 · Opened Jan 17, 2025
Clone system in CGT and LSR branches Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

PolicyEngine/policyengine-uk#990 · Opened Oct 29, 2024

A short digest of beginner-friendly GitHub issues.