ISA Allowance Calculator
Track current-year adult ISA subscriptions across account types. Lifetime ISA deposits use both the shared £20,000 limit and their own £4,000 cap.
Rule year: 2026/27 · GBP · Sources checked
Remaining adult ISA subscription allowance
Adult ISA eligibility and counted current-year subscriptions already established. Further Lifetime ISA age/account conditions supplied by the eligibility selector. No Junior ISA, flexible withdrawal replacement, transfer treatment, previous-year balances, investment return, excess correction or personalised account recommendation.
For informational purposes only. This estimate is not financial advice, a tax return, a payroll calculation or a lender decision. See the supported circumstances and exclusions below.
How this calculator works
The 2026/27 adult ISA subscription allowance is £20,000 shared across eligible accounts. Lifetime ISA deposits count within that total and also have a separate £4,000 annual cap. This tracker subtracts subscriptions entered for each account type and reports the narrower remaining Lifetime ISA room when further deposits are eligible. A potential 25% government bonus is shown on that eligible room; the bonus itself does not consume subscription allowance. Transfers and flexible-ISA replacement rules need separate treatment, so enter amounts already established as counting toward this year’s subscriptions.
Formula and rules
Remaining adult ISA room = max(0, £20,000 − counted subscriptions). Eligible Lifetime ISA room = min(remaining adult room, max(0, £4,000 − counted Lifetime ISA deposits)). Potential bonus = eligible room × 25%.
Assumptions and limitations
Adult ISA eligibility and counted current-year subscriptions already established. Further Lifetime ISA age/account conditions supplied by the eligibility selector. No Junior ISA, flexible withdrawal replacement, transfer treatment, previous-year balances, investment return, excess correction or personalised account recommendation.
Worked example
£6,000 cash ISA subscriptions, £4,000 stocks and shares subscriptions and £2,000 Lifetime ISA deposits use £12,000 total. £8,000 adult allowance and £2,000 eligible Lifetime ISA room remain, with a possible £500 bonus on that LISA room.
- Remaining adult ISA subscription allowance
- £8,000.00
- Remaining Lifetime ISA deposit room
- £2,000.00
- Potential bonus on remaining eligible Lifetime ISA room
- £500.00
- Total current-year subscriptions entered
- £12,000.00
Official sources and review
Reviewed against the sources below on 2026-10-06. Rates are held in versioned rule modules. Versioned rules, official source review and year-specific calculation tests.
- GOV.UK: ISA subscriptions ↗
2026/27 adult ISA limit £20,000 shared across account types, with £4,000 separate Lifetime ISA cap.
- GOV.UK: Lifetime ISA ↗
25% bonus, £4,000 annual deposit limit, age and account-opening eligibility.
Common questions
Does a Lifetime ISA have an extra allowance above £20,000?
No. Its deposits count within the shared adult ISA allowance and also face a separate £4,000 cap.
Does the government bonus use subscription room?
The Lifetime ISA bonus is not an ordinary personal subscription and is not counted by this tracker as using deposit room.
Should I count transfers as new subscriptions?
Transfer and flexible replacement rules can differ from new deposits. Establish the subscriptions counted for the year before entering totals.