Ranking · allowance size
UK ISA wrappers by annual allowance
The 2026/27 landscape places three wrappers at the £20,000 overall cap and two below it, what HMRC permits each saver to subscribe before the cap binds.
Annual subscription allowance by wrapper
2026/27 statutory caps, Junior separate; Lifetime nested in adult pot
The 2026/27 ranking
| # | Wrapper | Annual allowance |
|---|---|---|
| 1 | Cash ISA | £20,000 |
| 2 | Innovative Finance ISA | £20,000 |
| 3 | Stocks & Shares ISA | £20,000 |
| 4 | Junior ISA Separate from adult cap, per child | £9,000 |
| 5 | Lifetime ISA Sub-limit within £20k overall cap | £4,000 |
Source: gov.uk ISAs + HMRC ISA Managers Guidance Notes (2026/27 tax year).
How the overall £20,000 cap interacts with the rankings
The overall ISA cap of £20,000 applies across Cash, Stocks & Shares, Lifetime, and Innovative Finance wrappers in aggregate, not per-wrapper. A saver can subscribe £15,000 to a Cash ISA and £5,000 to a Stocks & Shares ISA in the same tax year, and the cap is satisfied. They cannot subscribe £20,000 to Cash and another £20,000 to Stocks & Shares; that would exceed the statutory cap and trigger a remediation from HMRC.
The Lifetime ISA sits within this overall cap but has its own sub-limit of £4,000. A saver maxing the LISA at £4,000 has £16,000 of remaining cap to split between Cash, S&S, and IFISA. The Junior ISA is separate, its £9,000 allowance is per-child and additive to the adult cap, so a parent can subscribe £20,000 to their own ISAs and £9,000 to each child's JISA in the same tax year.
Practical implications by saver profile
High-earning savers who maximise the £20,000 each year face a binary choice between Cash, S&S, IFISA, and a partial Lifetime ISA. The ranking matters because once the £20,000 is allocated, no further tax-sheltered subscription is possible until the next tax year on 6 April. Most savers in this position favour a Cash + Stocks & Shares mix based on time horizon, see our long-run returns research note.
First-time-buyer savers under 40 typically max the Lifetime ISA at £4,000 first (the 25% government bonus is unmatched elsewhere), then deploy the remaining £16,000 of cap across Cash and Stocks & Shares based on their property-purchase timeline. The LISA cap is the binding constraint, not the overall cap, for this profile.
Parents saving for children have the Junior ISA's separate £9,000 allowance plus their own adult £20,000, which gives a family of four (two parents, two children) a combined £58,000/year ISA capacity. The ranking by allowance size matters less than the total family allocation, both Junior ISA variants (Cash and S&S) share the £9,000 cap per child.
Year-on-year context
The £20,000 overall cap has held since the 2017/18 tax year. The Lifetime ISA's £4,000 sub-limit and the Junior ISA's £9,000 have similarly been stable since their respective introductions. The cap has not been indexed to inflation since 2017; in real terms the cap has eroded by approximately 20% under cumulative CPI to 2025. The Autumn 2024 Budget did not modify these allowances; a real-terms cap freeze through to 2028/29 is the current published plan.