The short version
- The calculators produce estimates from the published rules and the figures you enter. They are not quotations, assessments or decisions.
- Nothing on the site is financial, tax, legal, pensions, benefits or mortgage advice, and nothing is a personal recommendation.
- KnowMyPay is not authorised or regulated by the Financial Conduct Authority and does not arrange, promote or sell any financial product.
- KnowMyPay is independent of HM Revenue and Customs, the Department for Work and Pensions and every other public body. Official figures, payslips and award letters take precedence over anything shown here.
- Check the official source linked on each page, and take regulated advice, before acting on a figure.
Information, not advice
The site explains rules that apply to everyone in the same way and shows what those rules produce for the numbers entered. It does not know your full circumstances, does not ask for them, and cannot weigh them. A personal recommendation about what you should do with your money can only come from a person or firm authorised by the Financial Conduct Authority, a qualified accountant or tax adviser, or, for benefits, a welfare rights adviser. Free and impartial guidance is available from MoneyHelper, Citizens Advice and, for pensions, Pension Wise.
How the figures are produced
Each calculator applies the published rates and thresholds for the 2026/27 tax year, taken from gov.uk, HM Revenue and Customs, the Department for Work and Pensions, Ofgem and the other bodies named in the sources list on every page. The methodology page sets out the order of calculation. The figures assume a standard case unless the page says otherwise: for example a standard tax code, England, Wales or Northern Ireland rather than Scotland where the page offers no Scottish option, and no reliefs or deductions beyond those entered. Real payroll, tax assessments and benefit awards depend on details the calculators do not hold, so the result on your payslip, tax calculation or award letter will often differ, and the official figure is the correct one.
Accuracy and currency
Every rate is checked against its primary source before publication and the date of the last review appears in the footer of every page. Rates change at fiscal events and each April, and Ofgem's price cap changes quarterly; a figure can therefore be out of date between a government announcement and the next site review. Reasonable care is taken, but no guarantee is given that any page is complete, accurate or current at the moment you read it. If you find an error, please report it; corrections are made promptly and noted on the page.
Benefits, tax and pension decisions
Only the Department for Work and Pensions, HM Revenue and Customs, a local authority or the relevant scheme can decide what you are entitled to or owe. A calculator result is not evidence of entitlement and should not be relied on to make or refuse a claim, to stop a payment, to leave or take a job, to access a pension or to buy, sell or borrow. Some decisions described on the site, such as taking pension benefits, overpaying a student loan or transferring an ISA, cannot be reversed; take advice before making them.
Guides and worked examples
The guides describe the rules in general terms and use illustrative figures produced by the site's own calculators. They are written by the site's editor and are not reviewed by a regulated adviser. Examples describe typical cases, not yours, and figures described as illustrative, typical or assumed are not sourced statistics.
External links and third parties
Links to gov.uk and other sites are provided as sources and for convenience. KnowMyPay is not responsible for their content or availability and does not endorse any product, provider or service. The site currently carries no advertising or affiliate links; if that changes, the privacy policy and terms of use will say so.
Liability
To the fullest extent permitted by law, KnowMyPay and its editor accept no liability for any loss arising from use of the site or reliance on its content. This does not affect any liability that cannot be excluded by law. The terms of use set out the position in full.
Contact
Questions about this disclaimer, or a report of an incorrect figure, can be sent to enquiries.csr@gmail.com. See also the about and editorial policy, privacy policy and terms of use.