Tools · 2026/27

PlainISA Tools

Turn the £20,000 annual ISA cap into concrete numbers. Model growth, pick a wrapper with a six-question wizard, or compare all five HMRC types side by side.

Open calculator → Run decision engine

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.

5 wrappers · 3 interactive tools

PlainISA tools cover 5 HMRC ISA wrappers under the £20,000 adult cap for 2026/27. Use the calculator for year-by-year growth, the decision engine for a six-question fit, or compare for side-by-side rules. 3 of 5 wrappers carry a cited typical return; 1 carry a government bonus.

  • 3/5 with a typical return %
  • 1/5 with an HMRC bonus flag
  • 2026/27 registry coverage counts

What these tools answer

5 HMRC ISA wrappers share one adult pot of £20,000. The tools below map that cap onto growth, fit, and side-by-side rules without inventing products or rates.

5
Wrappers in the registry
3/5
Carry a typical return %
1/5
Carry a government bonus
4/5
Flagged FSCS-protected

Coverage counts are live COUNTs from the isa_types table. Rates come from HMRC guidance and cited return series, not broker quotes.

Model growth before you open a tool

Set contribution, horizon, wrapper, and return rate. The full calculator opens with your 2026/27 inputs pre-filled.

Runs on the server. Nothing stored beyond this navigation.

Open a wrapper rule record

Jump straight to allowance, bonus, lock-in, and FSCS fields for one HMRC ISA type. Same registry the compare table uses.

The three interactive tools

What a wrapper lookup returns

Share of the 5 HMRC ISA types carrying each independently checkable field. Base record is always 100%; deeper layers thin out where HMRC does not publish a single figure.

of wrappers

What this shows Every wrapper has a base HMRC record. Other fields appear only where the source material provides a checkable value for that wrapper.

Source PlainISA isa_types registry (HMRC-sourced) As of 2026-08-15

Typical return % for wrappers with a published figure (2026/27)

Only wrappers with a non-null typical_return_pct are plotted. LISA and JISA omit a single figure because return tracks the chosen cash or investment holding.

typical annual return

What this shows Only 3 of 5 wrappers have a published typical return field. The figure is a registry field, not a forecast or a recommendation.

Source PlainISA isa_types.typical_return_pct As of 2026-08-15

Return field is not HMRC bonus

IFISA leads the published typical return field at 6.5% (#1 of 3 wrappers with a figure) but carries no HMRC bonus; Lifetime ISA alone pays up to £1,000/year (#1 of 5) at a £4,000 sub-limit (allowance rank #5).

6.5%
IFISA return #1
3/5
Wrappers with return field
£1,000
Lifetime ISA bonus #1
#5
Lifetime ISA allowance rank

typical_return_pct is a registry citation field, not a forecast. Bonus figures are HMRC statutory caps. Not personal financial advice. LISA and JISA omit a single typical_return_pct because return tracks the chosen cash or investment variant.

Wrapper detail pages

Each tool links into the five wrapper pages when you need the full rule set. Coverage above is the same field set those pages render.

What to do with this

Pick a tool, then cross-check the wrapper rules before you subscribe or transfer.

Tools apply HMRC-sourced rules, not personal financial advice.

Download the HMRC ISA wrapper statistics extract cited on this page: hmrc-isa-wrapper-statistics.csv (Open Government Licence v3.0).

Every allowance, limit, and rate on PlainISA is rendered from the current gov.uk ISA rules and the HMRC ISA Managers Guidance Notes as recorded in our database, and no number is typed in by an editor. Coverage and return boards query the live isa_types and stats tables at render time; figures are not hand-typed in the template. Read our editorial standards and corrections policy, the methodology behind these numbers, or report a data error. Our database was last rebuilt on 15 August 2026.

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.