Conservative - Tax
Reform IR35 contractor rules
Loosen or simplify off-payroll working rules for contractors, with exact status tests unspecified.
Last updated: May 2026.
Tax baseline
Off-payroll rules seek to tax contractors working like employees broadly as employees. Reform may reduce compliance costs but can reopen gaps between employee and company-owner taxation.
- Contractors and clients gain flexibility.
- Revenue risk rises if rules weaken.
- Simplification may reduce admin costs.
Core trade-offs
The policy can reduce genuine compliance burdens for contractors and clients. If it weakens enforcement, more income may shift into lower-tax legal forms, raising an Exchequer cost.
- Contractors and clients gain flexibility.
- Treasury risks lower PAYE and NI receipts.
- Avoidance depends on detailed rules.
Fiscal impact by 2028-29
+GBP 0.2bn to +GBP 3.5bn. Central estimate: +GBP 1.0bn.
- Positive numbers mean net fiscal cost; negative numbers mean Exchequer savings.
- Main cost is lower PAYE and NI receipts.
- Compliance savings may raise activity modestly.
- Design determines whether reform is cheap or costly.
- This is not an official costing.
Economic impact by 2028-29
- Jobs: May support project contracting; employee substitution risk rises.
- Wages: Some contractors gain net income; employees may face unfair competition.
- Prices: Business project costs may fall where compliance costs drop.
- GDP / productivity: Could improve flexibility, but tax-motivated contracting lowers efficiency.
Assessment
A targeted simplification could reduce burdens without large revenue loss. A broad weakening of IR35 would likely cost revenue by encouraging employee-like work to be reclassified through lower-tax structures.
Confidence: Medium-low. HMRC evidence shows fiscal relevance; exact cost depends on reform design.
Main risks
- Revenue leakage: Employee-like income can shift away from PAYE and employer NI.
- Status disputes: Unclear tests create compliance costs and litigation.
- Labour arbitrage: Firms may substitute contractors for employees to cut tax and rights costs.
Safeguards
- Publish status tests before costing.
- Protect clear self-employment from excessive admin.
- Keep anti-avoidance rules for disguised employment.
Academic evidence
Adam, Miller and Pope, Institute for Fiscal Studies, 2017
Tax and legal form
Different tax treatment of employees, self-employed workers and owner-managers creates avoidance and incorporation incentives.
Relevant to IR35 reform and contractor taxation.
Saez, Slemrod and Giertz, Journal of Economic Literature, 2012
Taxable-income responses
Higher-income taxpayers respond more strongly to tax-rate changes through avoidance, timing and real behaviour.
Important where the policy changes top-pay, capital or business-tax incentives.
The Elasticity of Taxable Income with Respect to Marginal Tax Rates (2012)
UK government evidence
HM Revenue and Customs, 2025
IR35 reform update
HMRC updated evidence on the private-sector off-payroll reform and its revenue/compliance effects.
Anchors fiscal risk from weakening IR35.
Update to impacts of the 2021 off-payroll working rules reform (2025)
HM Revenue and Customs, 2025
HMRC tax ready reckoner
HMRC provides direct-effect estimates for illustrative changes to SDLT, VAT, fuel duties and other taxes.
Anchors tax costs before behavioural and macro adjustments.
Office for Budget Responsibility, 2026
OBR fiscal forecast
The OBR forecast sets the macro, borrowing and receipts baseline used for broad fiscal context.
Prevents treating tax cuts or spending changes as self-financing.
Sources
- PolicyLens methodology: Reform IR35 contractor rules Internal - PolicyLens, 2026
- Update to impacts of the 2021 off-payroll working rules reform UK government report - HM Revenue and Customs, 2025
- Direct effects of illustrative tax changes bulletin UK government statistics - HM Revenue and Customs, 2025
- Economic and fiscal outlook: March 2026 Fiscal forecast - Office for Budget Responsibility, 2026
- Tax, Legal Form and the Gig Economy Research report - Adam, Miller and Pope, Institute for Fiscal Studies, 2017
- The Elasticity of Taxable Income with Respect to Marginal Tax Rates Academic article - Saez, Slemrod and Giertz, Journal of Economic Literature, 2012
- Our Plan for Britain Party policy source - Conservative Party, 2026
Other Conservative policies
PolicyLens estimates are illustrative and should not be treated as official costings.