Methodology
How PayPath UK estimates take-home pay.
This page explains the current ruleset, what the calculators include, and what they deliberately leave out so users can treat the results as planning support rather than a payroll replica.
MethodologyRuleset 2025-26Last reviewed 13 March 2026Reviewed by PayPath UK editorial review
Current ruleset
- Tax year model: 2025-26
- Supported regions: Scotland and the rest of the UK
- Supported deductions: income tax, employee National Insurance, Plan 1, Plan 2, Plan 4, Plan 5, and standalone postgraduate-loan estimates
- All calculator results are annual models with monthly framing where useful
What is included
- Salary sacrifice is treated as reducing taxable pay and NI-able pay in the estimate
- Bonuses are modelled as additional annual earnings in the same tax year
- Student loan deductions are included when a supported single plan is selected
- Monthly figures are simple annual totals divided by 12
What is excluded
- Employer pension matching detail beyond the selected scenario
- Period-specific payroll quirks, emergency tax treatment, and payslip timing effects
- Equity, private healthcare, commute costs, overtime rules, and other non-cash benefits unless explicitly entered
- Combined undergraduate plus postgraduate loan deductions, personal allowance adjustments, and bespoke tax-code changes outside the standard model
Rounding and intended use
- Amounts are rounded for readability after calculation
- The figures are for planning and comparison, not payroll reconciliation
- Material decisions should be checked against your own circumstances and official guidance
- Read the disclaimer before relying on the figures for anything important