About / Why Trust This Site

Ian Billage

Trying to bring a little clarity to tax

Hi, I'm Ian Billage, the person behind Understanding Tax.

I've spent over 30 years in IT, including 15 years working in financial services, first as a developer and then managing development teams as a senior IT manager and CTO. Alongside that, I've always had a genuine interest in personal finance.

I built this site out of frustration. Working out if my own payslip was correct meant trawling the internet for answers, piecing together fragments from HMRC's own guidance, forums, and calculators that gave you a number but never really explained it. I wanted a single place that explains UK tax properly, with real worked examples, not just abstract rules.

One honest caveat: I am not an expert. Everything here comes from years of working this out for myself, checked directly against gov.uk and HMRC's own published guidance rather than secondhand summaries, as I explain below. The site provides information only. If you want advice, speak to a professional.

How I source content

Every page on this site is built primarily from official gov.uk guidance and HMRC's published rates and thresholds, cross-checked against at least two official sources before publishing. Where gov.uk's citizen-facing guidance doesn't cover a detail in full, I consult HMRC's technical manuals for accuracy and translate the result back into plain English. I don't cite legislation or internal manual references directly, only the plain-English explanation that comes from them.

Every page shows the tax year its figures apply to and when it was last reviewed. UK tax rates change every tax year (from 6 April), so I review and update figures at each tax-year boundary. See the full Disclaimer for what this site is, and isn't.

What this site is not

This site is general information, not personalised advice, and doesn't file returns on your behalf. It isn't a substitute for speaking to a qualified accountant or tax adviser about your own circumstances. Read the full Disclaimer for detail.

Support this site

Understanding Tax is free to use, and always will be with no paywall or login required. If it's helped you make sense of your payslip or your tax code, and you'd like to help towards its running costs, you can buy me a coffee. It's entirely optional, and never expected.

Get in touch

Spotted something that looks wrong, or have a suggestion for a page I should cover? See the Contact page.