ISA Allowance Checker (UK)
See how much of this tax year's ISA allowance is left, from what you have already paid in. The page also shows an average monthly amount: the remaining allowance divided evenly over the months left.
- Free
- No sign-up
- Uses the 2026-27 rules
Results are estimates only and not financial advice.
ISA Allowance Checker: how much of the £20,000 allowance is left
ISA Allowance Checker
Allowance remaining
Average per month if the remaining allowance is spread evenly
The Advanced ISA Planner compares two scenarios over a longer time horizon; the figures are illustrations, not forecasts (one-off £14.99, no subscription).
Advanced ISA Planner
Compare ISA scenarios side by side
£14.99 one-off, no subscription
Once you know how much allowance is left, the Advanced ISA Planner can model how contributions to different ISA types could develop over several tax years.
When a single calculator is not enough, the Advanced ISA Planner lets you set up longer-term scenarios, combine different ISA types, including cash ISAs, and model multiple tax years in one place.
- Combine Cash and Stocks & Shares ISAs
- Model multiple tax years and allowances
- Adjust returns, contributions, and time horizons
- Compare scenarios side by side
A paid tool: a one-off purchase of £14.99, with no subscription. The free calculators are separate from the planner. See the refund policy. Figures are illustrations, not forecasts.
What is the ISA allowance?
The ISA allowance is the most you can pay into ISAs in one tax year (6 April to 5 April). For 2026-27 it is £20,000, shared across all your ISAs, and any part you don't use cannot be carried forward to the next tax year.
Use this ISA Allowance Checker to see how much of the £20,000 annual ISA allowance you have used this tax year and how much is left. You do not have to use the full allowance; how much to pay in depends on your own circumstances.
The tool works out the part of the annual allowance that has been used and the part that is left. It is for UK savers and investors who pay into cash or investment ISAs.
If you’re modelling long-term growth scenarios, explore the Advanced ISA Planner. For a full breakdown of ISA rules and limits, visit our ISA Guides.
How to use the ISA Allowance Checker
- Enter how much ISA allowance you've already used this tax year
- Select how many months remain until the end of the tax year
- See the average per month if the remaining allowance were spread evenly over those months
ISA allowance rules for 2026-27
- The £20,000 allowance covers Cash ISAs, Stocks and Shares ISAs, Innovative Finance ISAs and Lifetime ISAs combined. Lifetime ISA payments count towards it, up to £4,000 a year.
- You can split the allowance across several ISAs, including more than one of the same type, but you can only pay into one Lifetime ISA a year (GOV.UK: how ISAs work).
- Transferring an existing ISA to a new provider through the ISA transfer process is not a new payment; withdrawing and paying the money back in may use up allowance (GOV.UK: transferring your ISA). Moving shares you already hold outside an ISA into one, known as a bed and ISA, does use allowance.
- Junior ISAs have their own £9,000 allowance per child, separate from yours.
- This checker uses the overall £20,000 allowance. From 6 April 2027, savers under 65 will be able to put no more than £12,000 a year of it into cash ISAs (GOV.UK). See the cash ISA limit from April 2027 explained.
- Our reference page lists all ISA rules for this tax year and the next, each with its gov.uk source.
ISA rules on this page are correct as of 26 September 2026. For every rule with its gov.uk source, see ISA rules at a glance.
Where to go next
Review & adjust
Change the number of months or the amount already paid in and run it again to see how the monthly figure changes.
Cash and investment ISAs
The allowance can be split across the different types of ISA, including Cash ISAs and Stocks and Shares ISAs, within the limits that apply to each type. These are set out on the ISA rules page. The Stocks and Shares ISA Calculator shows an illustration of how investments could grow at a rate you enter; it is not a forecast.
Longer-term illustrations
The ISA Calculator illustrates how contributions could grow over time at a rate you enter. The Advanced ISA Planner, a paid tool, compares two scenarios side by side. Both show illustrations, not forecasts.
Tax-year reminder emails
Get a short email before the tax year ends on 5 April and when the new one starts on 6 April.
We send up to four emails a year: three before the tax year ends (8 weeks, 3 weeks and 1 week before) and one on the first day of the new tax year. Each one states the tax-year dates and the ISA limits for that year, with a link to the ISA rules page. We send nothing else to this list.
General information only. Not financial advice.
ISA Allowance Checker FAQs
The ISA Allowance Checker shows how much of your annual ISA allowance you have remaining and the average per month if that amount were spread evenly over the months left in the tax year.
No. This tool does not model investment returns or growth. It shows only how much of your ISA allowance is left in the current tax year and the average per month if the remaining amount were spread evenly.
No. The calculator shows an average monthly figure. You can invest more in some months and less in others, as long as your total contributions stay within your ISA allowance.
This calculator uses the current UK ISA allowance of £20,000 per tax year. Allowance limits may change in future tax years.
No. This tool does not include platform fees, fund charges, or investment performance. It is designed for allowance planning only.
No. ISA Plan provides educational calculators and planning tools only. The results are estimates and do not constitute financial advice.