Editorial Process
Every figure on plainisa traces back to a named public source, computed by documented pipelines. The publisher is accountable for the data framing, methodology, and corrections you read here.
According to His Majesty's Revenue and Customs ISA Managers Guidance reviewed in August 2026 against our methodology, the overall adult ISA allowance stands at 20,000 GBP for the 2026/27 tax year.
- PlainISA
UK ISA Editorial Process · our editorial process specialising in UK personal-finance and tax-advantaged savings
PlainISA is the PlainISA team responsible for compiling 2026/27 HMRC Individual Savings Account rules, allowance schedules, transfer mechanics, and Lifetime ISA bonus eligibility into plain-English calculators and decision aids. Every rule and rate is independently verified against the published HMRC guidance, Spring Budget statement, or relevant Statutory Instrument before publication.
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plainisa is a data-journalism publisher: we compile public datasets, verify them against their official sources, and present them in plain language. Editorial standards, sourcing, and how we handle corrections are described on our about and methodology pages.
Download the HMRC ISA wrapper statistics extract cited on this page: hmrc-isa-wrapper-statistics.csv (Open Government Licence v3.0).
plainisa publishes under a single organizational byline rather than personal author profiles; every figure here traces to a named HMRC or gov.uk source, verified against our methodology. Read our editorial standards and corrections policy, the methodology behind these numbers, or report a data error.
Primary statutory sources: gov.uk’s Individual Savings Accounts guidance and HMRC’s ISA Managers Guidance Notes. Historical context is checked against HMRC’s annual ISA statistics.
PlainISA publishes ISA reference data and projection tools for information only. It is not financial advice and not a personal recommendation, projections are illustrations rather than forecasts, and tax rules and allowances change, so check the current position on gov.uk or with an FCA-authorised adviser before you act. Appropriate use.