Navigate the complex financial landscape of UK contracting. Whether assessing a contract’s IR35 status, deciding between a personal service company (PSC) and an umbrella company, determining your target day rate, or auditing an umbrella payslip line-by-line, our 2026/27 contractor toolset delivers statutory, penny-accurate guidance with complete client-side data privacy.
Contractor Calculation Tools
Contractor Take-Home Calculator
3-Mode comparison: Outside IR35 (Ltd Co), Inside IR35 (Umbrella), and PAYE Permanent equivalent with live IR35-shock analysis.
Compare 3 Modes → Extraction ToolSalary & Dividend Optimiser
Interactive slider to model director salary extraction vs dividends, balancing Corporation Tax, Employer NI, and Dividend Tax.
Optimise Extraction → Reverse SolverWhat Day Rate Do I Need?
Reverse-engineer your required contractor day rate and hourly billing from your target monthly or annual net take-home pay.
Calculate Day Rate → Audit ToolUmbrella Payslip Checker
Verify your umbrella payslip line-by-line. Flags hidden fees, non-statutory deductions, and Employer NI calculation errors.
Audit Your Payslip → Statutory GuideIR35 Rules Explained
Detailed guide on off-payroll working rules, Status Determination Statements (SDS), CEST tests, and client disagreement rights.
Read Guide → Comparative GuideInside vs Outside IR35
Worked financial case studies demonstrating the annual take-home gap across day rates from £350 to £800/day.
Read Comparison →
Also see our Contractor IR35 Calculator — IR35-status focused walkthrough.
Construction subcontractor? Try our CIS Tax Calculator.
Running a limited company? Track your statutory filing obligations with our Contractor Compliance Deadline Tracker.
Buying a home? Calculate your borrowing power with our Contractor Mortgage Calculator.
2026/27 Statutory Operating Parameters for Contractors
Key Legislative Benchmarks
- Employer National Insurance: 15.0% on earnings above the secondary threshold (£5,000/year). Inside IR35 contractors bear this deduction from their assignment rate.
- Employment Allowance (£10,500): Excluded for single-director PSCs with no other employees under Section 165 National Insurance Contributions Act 2014 rules.
- Apprenticeship Levy: 0.5% on annual paybills over £3 million (passed on by all commercial umbrella companies).
- Corporation Tax: 19% small profits rate up to £50,000, 25% main rate above £250,000, with marginal relief (3/200 fraction) between £50,000 and £250,000 for standalone companies.
- Dividend Tax Rates: 10.75% (ordinary rate), 35.75% (upper rate), and 39.35% (additional rate) above the statutory £500 annual Dividend Allowance.
- 5% Expenses Allowance Abolished: For public sector and medium/large private clients, the historical 5% unvouched expenses allowance under Chapter 8 ITEPA has been completely abolished by HMRC.
Complete Client-Side Data Privacy
All calculations run 100% locally in your browser. No rates, salaries, contracts, or personal data are ever transmitted to our servers or stored in any remote database. Scenario data is saved exclusively on your device via browser local storage (ukc_contractor_scenarios_v1).