interactive investor Stocks & Shares ISA

An interactive investor Stocks & Shares ISA is a tax-free investment account from the platform most people know as ii. You hold investments inside it, and the growth and income they produce are not taxed. It is not a savings account: the value can fall as well as rise, and that risk stays with you.

The account's defining feature is how it is priced. Rather than taking a percentage of your money each year, ii charges a flat monthly subscription, and the Stocks & Shares ISA sits inside that fee. The platform's own site has today's figures for each plan and what it covers. ii has been running since 1995 and says it has over 500,000 investors, more than half of whom have been with it for over 10 years¹.

This page covers what the account is, how the fee structure works, what you can hold, who can open one, how to apply or transfer an ISA in, and what happens if something goes wrong.

What it is and who it is for

A stocks and shares ISA is a tax-free investment account that lets you put money into a range of different investments². The interactive investor version is one of these, run by a platform whose selling point is flat-fee pricing rather than a percentage charge. ii describes itself as the UK's leading flat-fee investment platform¹.

The account suits people who want to choose their own investments and hold them in one place. ii does not offer advice, and says any decision to invest is based on your own personal circumstances, including how long you intend to invest³. That matters: this is a self-directed account, so the choices are yours.

It also suits people who hold several accounts. ii's flat fee covers a Stocks & Shares ISA, a Trading Account and a Junior ISA, and the platform says you do not pay any more for an ISA once you have an account³. A Personal Pension can be added for an extra monthly charge³.

It is less suited to someone who wants a cash ISA, a guaranteed return, or someone who wants a provider to pick investments for them. ii does run a managed ISA, which is a separate product with its own page.

How it works

You open the account, pay money in, and use it to buy investments. ii offers its own starting points: Quick-start Funds, which are ready-made fund choices, and the ACE40, a specialist list of recommended sustainable funds that Which? describes as unique to the platform⁶. You can also buy individual shares, investment trusts and funds.

The account is not a flexible ISA. That means if you withdraw money, you cannot replace it using the same year's allowance⁷. Withdrawals themselves are tax-free: you do not pay tax when you take money out of an ISA, and profits made inside the account are not taxable⁷.

Timing matters on withdrawals. If you request a cash withdrawal before 2pm, ii says you will usually receive it the next working day; after 2pm, within two working days⁷. If you are selling shares first, the cash is not available to withdraw until the trade has settled⁷. Money can be withdrawn into an account held in your name⁷.

ii customers can also access new gilt and UK Treasury Bill issues directly from the Debt Management Office, buying at the non-competitive auction price, which is the average accepted price for the gilt⁸. No prospectus or offer documentation is released for these, so ii tells customers to consider the risk and return profile carefully⁸.

How the fees and charges work

ii's pricing is a flat monthly subscription rather than a percentage of your portfolio. The platform says it charges a flat monthly fee which covers your ISA, Trading Account and Junior ISA³, and that once you have an account you do not pay any more for an ISA³. It describes the structure as flat fee pricing, so you know exactly what you pay as you grow your wealth⁹.

The subscription is charged quarterly to cover the cost of services including the administration of your funds³. The platform's site has today's figures for each plan and what each one includes.

Trading is charged separately. ii gives one free trade per month to buy or sell any investment, including Quick-start Funds, and additional trades usually cost £3.99³. Regular investing is free to trade³. A Personal Pension, if you add one, carries an additional monthly charge³.

Two things are worth knowing before you compare platforms. First, most investment platforms will not charge extra for an ISA¹⁰, so the ISA wrapper itself is rarely the thing that separates providers. Second, exit fees vary: Which? found some providers charging exit fees ranging from £15 to £30 per holding, while most charge nothing¹¹. Those are the costs that bite when you leave, not when you join.

What you can hold

A stocks and shares ISA can hold a range of investments, and ii's account is built around self-directed choice. Alongside individual shares and funds, the platform offers investment trusts and its own curated lists.

The ACE40 is ii's specialist list of recommended sustainable funds, which Which? describes as the only such list offered by a platform⁶. Quick-start Funds are ii's ready-made fund options, and the platform gives one free trade a month to buy or sell them³. ii also runs an ethical ISA and an AIM shares ISA, both separate products with their own pages.

For investors who want government debt, ii customers can access new gilt and UK Treasury Bill issuance directly from the Debt Management Office⁸. Gilts are bought at the non-competitive auction price, the average accepted price, with the yield based on the average of the other successful bids⁸. Treasury Bills are allocated differently: the DMO accepts bids and allocates at the lowest bid yields until the target issue size is reached, with each successful bidder filled at the yield of their own bid⁸. Once allotment is finalised, your allocation and cash are exchanged for the security and placed in your account ready for the first day of trading, known as Strike Day⁸.

If you hold shares from an employee scheme, ii only accepts shares into an ISA from a Save As You Earn or Share Incentive Plan scheme¹².

Who can apply and how to apply

To open an investment account with ii you must be 18 or over and either a UK, Channel Islands or Isle of Man resident³. You will need your address details for the last three years, your National Insurance number and your debit card details³.

The application is online. ii says you will need your address details, debit card and National Insurance number, and then you can start your application¹. The platform does not offer advice, and states that any decision to invest is based on your own personal circumstances³.

If you already hold an ISA elsewhere, you can transfer it in rather than withdrawing and reinvesting. ii says existing customers can log in, click the cash and transfers menu and select transfer in¹. Transfers are arranged between the two providers, so the money moves directly and does not use up your allowance again. Which? has a separate guide to how ISA transfers work if you want the mechanics before you start.

How your money is protected

Two different things are being protected here, and they work differently.

Your investments are held separately from ii's own assets, which helps protect them if ii were to fail⁴. That separation is the main protection for the investments themselves: they belong to you, not to the firm. Cash is treated differently again. It is held as client money under FCA rules and held with banks covered by the FSCS deposit protection scheme⁴. ii states that it is FCA regulated and FSCS protected¹⁴.

ii states that it is FCA regulated and FSCS protected¹⁴. The firm behind the brand is Interactive Investor Services Limited, authorised by the FCA with firm reference number 141282, and its status has been authorised since 1 December 2001⁵. The company is active on the Companies House register, company number 02101863, incorporated on 20 February 1987¹⁵. You can check the FCA Register entry yourself using the reference number.

What protection does not cover is investment performance. If the value of what you hold falls, that loss is yours. FSCS protection covers the failure of a firm, not a bad investment decision or a market downturn.

On security, ii says the platform uses encryption, security checks and 24/7 monitoring, and offers a privacy mode that hides sensitive information such as portfolio values so you can use the app in public⁴. The platform says it will never call from a number other than 0345 607 6001, never ask for your password, never give unsolicited financial advice, and never get in touch through social media¹⁶. It warns that investment scams using social media and WhatsApp are on the rise, and says to report fraud on 0300 123 2040¹⁶.

Problems, complaints and getting help

Start with ii. The firm takes complaints by secure message through your account, by phone on 0345 607 6001, or in writing to Customer Services, interactive investor, 4th Floor, 3 South Brook Street, Leeds LS10 1FT¹⁷. Secure messaging is the platform's preferred contact method¹⁶.

If the outcome is not satisfactory, the complaint can go to the Financial Ombudsman Service, which is free to consumers. The ombudsman has a dedicated page for stocks and shares complaints, and says that if the complaint is about stocks and shares held in an ISA, its separate consumer page about ISAs applies¹⁸.

Complaint volumes give a sense of scale. In the first quarter of 2026/27 the ombudsman recorded 392 complaints about Stocks and Shares ISAs and 61 about investment platforms¹⁹. In 2024/25, Stocks and Shares ISAs were the most complained-about investment product, with 1,655 new complaints²⁰. ii's own published complaints data for 1 January to 30 June 2026 shows 4,069 complaints opened in the investments category, where the main cause was delays and timescales, and 411 in the SIPP and decumulation category, where the main cause was general administration and customer service¹⁷.

If an account holder dies, a solicitor, next of kin or an executor can notify ii, providing written confirmation and an original or certified copy of the death certificate²¹. Copies can be certified by an FCA regulated body such as a bank or solicitor²¹. ii will update accounts held in the deceased's sole name and block them from trading, holding funds pending legal documentation²¹. A court sealed copy of the Grant of Probate, or Grant of Confirmation in Scotland, is needed, and up to four executors can be named²¹. Where no will exists, a close relative can apply for a Grant of Letters of Administration²¹.

For free, impartial help with money questions generally, MoneyHelper is the government-backed service. For debt problems, StepChange and Citizens Advice offer free advice.