About PlainISA

Last updated:

Our mission is to make the UK Individual Savings Account framework transparent and freely accessible to every household. PlainISA helps savers, journalists, and policy researchers find, compare, and understand the four ISA product types (Cash, Stocks & Shares, Lifetime, Innovative Finance), the annual £20,000 subscription allowance, and the HMRC reporting rules, without paywalls, account requirements, or advisor-style product steering.

PlainISA provides allowance calculators, decision aids, and goal-mapped wrapper choice tools for UK savers navigating the four ISA product types. Every figure is sourced from HMRC publications or the gov.uk Individual Savings Accounts service. We do not recommend specific products, providers, or advisers, we explain the framework so savers can make informed choices.

Our Data

PlainISA's content derives from the HMRC ISA Manual and the gov.uk Individual Savings Accounts service, plus periodic statistical releases from HMRC's annual ISA Statistics publication. This includes:

  • ISA wrapper mechanics: Cash, Stocks & Shares, Lifetime, and Innovative Finance ISA rules, allowance caps, transfer mechanics.
  • Annual allowance and sub-limits: the £20,000 overall cap and £4,000 LISA sub-limit, sourced from the current Finance Act.
  • Bonus and penalty mechanics: Lifetime ISA 25% government bonus, 25% early-withdrawal charge, withdrawal scenarios.

Methodology

We translate HMRC source documentation, the ISA Regulations 1998 (as amended), and gov.uk consumer guidance into plain-language explainers, decision tools, and calculators. No HMRC source content is paraphrased into figures, numbers are quoted directly from the statutory source and date-stamped. For full sourcing, see our methodology page.

Updates

HMRC publishes ISA Statistics annually, typically in late summer covering the prior tax year with provisional figures and the year before that with reconciled figures. The ISA Manual itself is updated on rolling basis as policy changes; we monitor the changelog and refresh our content within 30 days of material updates.

Not Affiliated

PlainISA is not affiliated with HMRC or any government agency. We are an independent data portal providing public information in a more accessible format.

Who Built This

PlainISA is published by PlainISA, an independent data-journalism team that compiles, verifies, and contextualizes public datasets. We do not accept compensation from entities we cover.

Editorial Process

PlainISA's reference data is manually curated, not scraped or auto-fetched: our editorial process reads the HMRC ISA Manual and the relevant gov.uk pages directly and enters each allowance cap, bonus rate, and statutory threshold into our database with its source URL and the date it was checked. Numbers are never altered between source and display, briefs and explainers are then drafted and reviewed by our editorial process for accuracy, plain-language clarity, and consistency with the underlying regulation. Our methodology page documents the full source-to-publication chain.

Disclaimer

This site is for informational purposes only. Data comes from UK government (HMRC and gov.uk) sources and is presented as-is. While we strive for accuracy, we cannot guarantee completeness. Always verify important information with official sources.

Contact

For questions or feedback, email hello@plainisa.co.uk or use our contact form.

Who Publishes This

PlainISA is operated by Kiznis Studio, an independent data-engineering studio (solo-operated). Questions, corrections, and accountability inquiries can be sent to hello@plainisa.co.uk.