Budget Day: How Foliopeak Keeps Its Figures Right

A Budget is the one day the numbers underneath a finance app can all move at once, and there was one on 28 October 2026. Here is what Foliopeak does on a Budget day, so you know what to expect from the app and how quickly.

Every allowance, rate and threshold the app uses lives in a single file of tax figures: the £20,000 ISA allowance, the £60,000 pension annual allowance, the £3,000 Capital Gains Tax allowance, the income tax bands, the National Insurance rates, the student loan thresholds and the rest. The calculators, Summit's tax-year card, Cairn's answers in your own AI assistant, the Learning Hub articles and even this blog read from it. A change made there is a change made everywhere, and nothing can quietly keep an old number.

Announcements are checked against the Treasury's own documents, not the news coverage. Each change gets a start date, because most of them begin on a 6 April one, two or three years out, and the app changes a figure on the day it takes effect - not before. The Learning Hub article What changed in the Budget is rewritten within a day, in order of when each change starts, and the page for what changes on 6 April lists the ones still to come.

Then the check. Every figure in that file is compared with HMRC's published rates for 2026/27, the app's automatic tests run (they include worked examples checked against HMRC's guidance), and the date of that check is recorded beside the figures. Each tax calculator on the public Learning Hub then says which tax year's rates it uses.

It does not guess. If a change is announced without the detail needed to work it out, the article says so and the calculator keeps the current rule until the detail is published. And it does not advise: the app tells you what a change does to an allowance you have, and leaves what to do about it to you.