Sterlingsum
How we check our figures
Where our numbers come from, how we keep them current, and what to do if you spot a mistake.
Where our figures come from
Tax rates, allowances, benefit amounts and deadlines come from official sources: GOV.UK and HMRC for tax, National Insurance, pensions and benefits, and the organisations that run each service. Where a rule differs in Scotland, Wales or Northern Ireland, the page says so or points to the official source for that nation.
Phone numbers and opening hours on our Free help page were checked on each organisation's own website, not copied from directories.
How we keep them up to date
- Most rates and thresholds change at the start of the tax year in April. We recheck the figures then and update the calculators and guides.
- Pages that quote figures say which tax year they apply to, for example 2026/27.
- Phone numbers and opening hours on Free help are rechecked every few months.
What our calculators do
They give estimates from the figures you enter, using the rules published for the tax year shown. They cannot see your tax code, your full circumstances or changes made after the page was last checked, so your payslip, tax code or official notice always comes first. Each calculator page explains what it assumes.
What we are not
Sterlingsum is an information site. We are not authorised to give tax, legal, financial, debt or immigration advice, and nothing on the site is a recommendation to buy a product. Where you need advice, our pages point to free, regulated services.
Spotted a mistake?
Please tell us through the contact page. Say which page and which figure, and ideally link to the official source. We will check it and correct the page if it is wrong.