Everything runs in your browser
Calculations happen on your device using JavaScript. We do not operate a backend API for planner inputs. Results appear instantly from the numbers you enter; nothing is uploaded for processing.
UK rules and tax years
Tools that involve tax or statutory thresholds use published UK figures for the selected tax year where applicable. For example, the Take-Home Salary Calculator uses Income Tax and National Insurance bands for England, Wales, Northern Ireland, or Scotland when selected. The Student Loan Repayment Planner uses plan thresholds for the tax year you choose. Stamp duty tools use current residential bands for England & NI, Scotland, or Wales.
Each tool page lists its own limitations. Rules change — always confirm against HMRC, the Student Loans Company, or your lender before acting on a projection.
Projections are not predictions
Long-range tools such as the Retirement Planner and Compound Interest Calculator apply the growth rates and contribution assumptions you enter. They illustrate scenarios; they do not forecast markets, salary progression, or future legislation.
Local storage
Form values and preferences (theme, reading comfort) may be saved in your browser’s localStorage
so you can return later. You can clear this at any time through your browser settings. See
privacy and terms for cookies and analytics.
Updates
When UK rates or tax years change, we update the relevant calculator logic and note the assumption on the tool page.
Major updates are reflected in the site sitemap lastmod dates.