Interactive Investor
vs AJ Bell (2026)
Both are established, FCA-regulated UK platforms trusted by long-term investors. The structural difference that determines almost everything: ii charges a flat monthly fee. AJ Bell charges a percentage of your portfolio. This guide breaks down which model wins — for your ISA, SIPP, and portfolio size — with real cost scenarios.
Some of the links on this site are affiliate links, meaning we may earn a commission at no extra cost to you if you sign up through them. This does not affect our reviews or recommendations — we only feature products we genuinely believe are useful for investors. This site provides educational content only, not personalized investment advice. Investments can lose value and past performance does not guarantee future results. You are responsible for your own financial decisions and for confirming the tax and legal rules that apply in your country.
TL;DR
- Multi-account holders — one flat fee covers ISA, SIPP, and GIA
- SIPP investors with balances above ~£29,000
- Investors using regular automated contributions (free on all plans)
- Frequent traders — lower per-trade commission
- Large portfolios and pension consolidation
- Single ISA investors — custody capped at £42/year for ETFs/shares
- Lifetime ISA (LISA) — ii does not offer one
- Beginners who prefer no monthly subscription to justify
- Investors who trade infrequently and hold one account
- Those who want a cleaner, more modern app experience
The one structural difference that drives everything
Before comparing any specific fee, you need to understand how these two platforms are fundamentally designed to charge. Get this right and the rest of the comparison falls into place.
You pay £5.99/month on the Core plan — regardless of how much you hold. That single fee covers your ISA, SIPP, GIA, and any additional accounts simultaneously. As your portfolio grows, your platform cost stays exactly the same.
The implication: a £500,000 portfolio pays the same £71.88/year as someone with £50,000. The flat-fee model becomes dramatically more efficient at scale — and especially for multi-account investors.
AJ Bell charges 0.25% of your portfolio value per year, with caps applied per account: ETFs and shares in an ISA or GIA cap at £42/year. ETFs and shares in a SIPP cap at £120/year. For funds (OEICs, unit trusts), no cap applies.
The implication: those caps make AJ Bell effectively flat for large ETF/share portfolios within a single account — but the caps stack independently per account, which matters significantly for ISA + SIPP holders.
Full fee comparison (2026)
ii data reflects the February 2026 restructure. Core plan shown for ii — see the ii full review and AJ Bell review for all plan tiers.
| Fee | Interactive Investor (Core) | AJ Bell |
|---|---|---|
| Monthly platform fee | £5.99/month (£71.88/yr) Covers all accounts simultaneously |
£0 Custody charge applies instead |
| Custody fee | 0% Included in flat monthly fee |
0.25% p.a. ETF/shares ISA cap: £42/yr · SIPP cap: £120/yr · Funds: uncapped |
| Trade commission (UK & US) | £3.99 per trade | £5.00 per trade £3.50 with 10+ trades in prior month |
| Trade commission (International) | £9.99 per trade | £7.99 per trade (Plus plan) Check AJ Bell for exact current tiers |
| Regular investing | £0 — free on all plans | £1.50 per order |
| FX markup | ~0.75% (Core) 0.25% flat on Premium plan |
Tiered: 0.75% (≤£10k), 0.50% (£10k–£20k), 0.25% (above £20k) Applied per trade on non-GBP instruments |
| Commission-free ETFs | No (regular investing is free) | No (regular investing at £1.50) |
| Fractional shares | No | No |
| Free monthly trades | None on Core or Plus Premium: 2 free trades/month |
None |
| Minimum deposit | £0 (£25/month for regular investing) | £0 |
| Regulation & protection | FCA regulated · FSCS up to £85,000 | FCA regulated · FSCS up to £85,000 |
Who each broker is built for
The “better” broker is a function of your account structure, not just the headline fee. Here’s how each platform maps to different investor types.
| Investor type | Likely better fit | Why |
|---|---|---|
| Single ISA, ETF/shares, passive | AJ Bell | £42/yr custody cap beats ii’s £71.88/yr flat fee |
| ISA + SIPP combined | ii | One fee covers both; AJ Bell caps stack per account |
| SIPP above ~£29,000 | ii | 0.25% × £29k = £72.50/yr — flat fee already competitive |
| Regular automated investing | ii | Free on all plans vs £1.50/order on AJ Bell |
| Frequent trader (20+ trades/yr) | ii | £3.99 vs £5.00 per trade compounds at volume |
| Fund (OEIC) investor at scale | ii | AJ Bell’s 0.25% on funds has no cap — flat fee wins clearly |
| Lifetime ISA (LISA) | AJ Bell | ii does not offer a LISA — no alternative here |
| Beginner, smaller portfolio | AJ Bell | No monthly fee to justify; cleaner onboarding experience |
| Large pension consolidation | ii | Flat fee scales; covers all pension admin under one plan |
| ISA + SIPP + GIA | ii | AJ Bell charges three separate custody fees; ii charges one |
What each platform offers
The account range is broadly similar — with one material gap that may settle the decision for some investors.
- ✅ Stocks & Shares ISA
- ✅ SIPP (Self-Invested Personal Pension)
- ✅ Junior ISA (JISA)
- ✅ General Investment Account (GIA)
- ✅ Joint accounts
- ✅ Business/company accounts
- ❌ Lifetime ISA — not currently offered
- ✅ Stocks & Shares ISA
- ✅ SIPP
- ✅ Junior ISA (JISA)
- ✅ Junior SIPP
- ✅ General Investment Account (GIA)
- ✅ Lifetime ISA (LISA) — 25% government bonus
- ✅ “Dodl” app — simplified beginner-friendly sibling product
Investment range, tools, and platform experience
Both platforms go well beyond ETFs. The depth and framing differ — and so does the UX experience that shapes day-to-day investing.
- UK, US, European, and Asian market access
- ETFs, investment trusts, shares, bonds, OEICs
- Super 60 — vetted shortlist of funds and ETFs
- ACE 40 — ethical and sustainable investment list
- Model portfolios for passive investors
- Shareholder voting enabled by default (opt-out model)
- Morningstar data and research integration
- Multi-currency account capability
- UK, US, and European market access
- ETFs, shares, funds, investment trusts, bonds
- Favourite Funds — curated shortlist for DIY investors
- Ready-made portfolios for hands-off investors
- Shares Magazine (owned by AJ Bell) — in-house editorial research
- Cash Savings Hub — integrated savings rate comparison
- Better-rated mobile app experience vs ii
- Dodl app for beginners who want maximum simplicity
What you’d actually pay — annual platform cost
Scenarios assume ETF or share holdings (AJ Bell caps apply), 12 manual trades per account per year, and no regular investing orders. FX excluded. ii uses Core plan (£71.88/year).
| Scenario | ii Core (annual) | AJ Bell (annual) | Cheaper |
|---|---|---|---|
| ISA only — £10k, 12 trades | £71.88 + £47.88 = £119.76 | £25.00 + £60.00 = £85.00 | AJ Bell by £34.76 |
| ISA only — £30k, 12 trades | £71.88 + £47.88 = £119.76 | £42.00 + £60.00 = £102.00 cap kicks in at ~£16.8k |
AJ Bell by £17.76 |
| ISA only — £100k, 12 trades | £71.88 + £47.88 = £119.76 | £42.00 + £60.00 = £102.00 | AJ Bell by £17.76 |
| SIPP only — £20k, 12 trades | £71.88 + £47.88 = £119.76 | £50.00 + £60.00 = £110.00 | AJ Bell by £9.76 |
| SIPP only — £30k, 12 trades | £71.88 + £47.88 = £119.76 | £75.00 + £60.00 = £135.00 | ii by £15.24 |
| SIPP only — £100k, 12 trades | £71.88 + £47.88 = £119.76 | £120.00 + £60.00 = £180.00 cap kicks in at £48k |
ii by £60.24 |
| ISA £50k + SIPP £50k, 24 trades total | £71.88 + £95.76 = £167.64 | £42 + £120 + £120.00 = £282.00 | ii by £114.36 |
| ISA £100k + SIPP £100k, 24 trades total | £71.88 + £95.76 = £167.64 | £42 + £120 + £120.00 = £282.00 | ii by £114.36 |
| ISA + SIPP + GIA (any size), 12 trades total | £71.88 + £47.88 = £119.76 | £42 + £120 + £42 + £60 = £264.00 | ii by £144.24 |
The UK broker cost calculator lets you input your portfolio size, account mix, and trading frequency to compare ii, AJ Bell, and other UK platforms side by side.
Open UK cost calculator →ISA and SIPP — where the decision is usually made
AJ Bell’s ETF/shares custody in an ISA caps at £42/year — less than ii Core at £71.88/year. For a passive investor making 12 manual trades: AJ Bell (£102) vs ii (£119.76). AJ Bell saves roughly £18/year on a single ISA.
The regular investing wrinkle: ii offers free regular investing on all plans. AJ Bell charges £1.50/order. At 12 automated monthly contributions per year, AJ Bell adds £18 — fully wiping out its custody advantage. For investors who automate consistently, the ISA call is essentially a draw, or slight ii advantage.
AJ Bell charges 0.25% on SIPP assets (for ETFs/shares), capped at £120/year once your balance exceeds £48,000. But ii’s flat £71.88/year already beats 0.25% at a balance of ~£28,752. Above that crossover, ii is cheaper on custody alone — and the SIPP cap doesn’t help until £48k, by which point ii is £48.12/year cheaper per year (£120 vs £71.88).
Additionally, ii’s flat fee covers your ISA at no extra cost. Any investor holding both a SIPP and ISA should run the combined number — ii typically saves £100–£160/year in that scenario.
Pros and cons
- Single flat fee covers all accounts — major advantage for multi-account holders
- Free regular investing on all plans
- Lower per-trade commission (£3.99 vs £5.00)
- Stronger for SIPPs above ~£29,000
- Broader international and market access
- Super 60 and ACE 40 curated investment lists
- Shareholder voting included and active by default
- Fund investors benefit from flat fee at scale (no uncapped % drag)
- More expensive for a single small ISA vs AJ Bell’s capped custody
- No Lifetime ISA
- Platform can feel complex and data-heavy for first-time investors
- FX markup ~0.75% on Core — upgrade to Premium for 0.25%
- No monthly platform fee — lower barrier to get started
- Lifetime ISA (LISA) — the only option between these two
- ISA custody cap (£42/yr) makes it competitive for single-account ETF investors
- Better-rated mobile app experience
- Cash Savings Hub for comparing savings rates
- Dodl app for investors who want the absolute simplest experience
- Strong customer service reputation and well-established platform
- Junior SIPP available
- Custody caps stack per account — ISA + SIPP + GIA adds up to £204/yr custody before trading
- Regular investing costs £1.50/order (ii is free — this fully offsets the ISA custody advantage for frequent contributors)
- Fund investors pay 0.25% p.a. with no cap — disadvantageous at scale
- Higher per-trade commission (£5.00 vs £3.99)
- SIPP becomes more expensive than ii above ~£29k balance
Which broker should you choose?
The answer is almost entirely determined by your account structure and the size of your SIPP. Neither platform is categorically better — they serve different investor profiles.
- You hold (or plan to hold) both an ISA and a SIPP — the flat-fee advantage is clear and compounds as you accumulate
- Your SIPP balance is above ~£29,000, or will be within a few years of joining
- You invest via regular automated contributions — free on all ii plans, £1.50/order on AJ Bell
- You hold three or more account types (ISA + SIPP + GIA) — ii saves £140+/year vs AJ Bell stacking three custody fees
- You’re an active trader or invest internationally and value the lower per-trade commission
- You hold a mix of funds and ETFs — AJ Bell’s uncapped 0.25% on OEICs hurts at scale
- You’re consolidating multiple pensions into a single platform
- You’re investing only in a single ISA and don’t plan to open a SIPP on the same platform in the near term
- You want or need a Lifetime ISA — there’s no alternative between these two
- You’re a beginner who wants a lower-friction onboarding experience and no monthly subscription to justify
- You invest infrequently (a few trades per year) and the £1.06/trade commission difference doesn’t matter
- You want the Dodl app for maximum simplicity alongside a standard account
- You value the Cash Savings Hub and integrated editorial research from Shares Magazine
Ready to open an account?
If you hold ISA + SIPP, run the cost scenarios first — ii typically saves £100+ per year in that structure. If you need a LISA or are starting with a single ISA only, AJ Bell is the stronger starting point.
Go deeper
Frequently asked questions
Is Interactive Investor cheaper than AJ Bell?
It depends on your account structure. For a single ISA holding ETFs or shares, AJ Bell’s custody fee caps at £42/year — lower than ii Core at £71.88/year. AJ Bell wins on a single ISA regardless of portfolio size. But the moment you add a SIPP or second account, ii’s flat fee covers everything while AJ Bell’s caps stack independently per account. For ISA + SIPP holders, ii typically saves £100–£160 per year. See the scenario table above for specifics.
Which broker is better for an ISA?
For a single Stocks and Shares ISA with ETFs or shares, AJ Bell’s custody cap of £42/year is lower than ii Core at £71.88/year. On 12 manual trades: AJ Bell costs around £102/year vs ii’s £119.76. However, if you use regular automated investing, ii’s free regular investing (vs AJ Bell’s £1.50/order) can fully offset that gap — at 12 automated orders/year, AJ Bell adds £18, wiping out its custody advantage entirely. For ISA + SIPP combined, ii wins clearly in most scenarios.
Which broker is better for a SIPP?
Interactive Investor is generally better for SIPPs once your balance exceeds approximately £28,750. Above that level, ii’s flat fee of £71.88/year (Core plan) is lower than AJ Bell’s 0.25% p.a. charge. AJ Bell’s SIPP custody caps at £120/year for ETFs and shares — but even then, ii is £48/year cheaper at the cap. For investors holding both an ISA and a SIPP, ii’s advantage is even more pronounced: one flat fee covers both accounts simultaneously.
Does AJ Bell offer a Lifetime ISA?
Yes. AJ Bell offers a Stocks and Shares Lifetime ISA with the 25% government bonus on contributions up to £4,000 per tax year. To be eligible you must be under 40 when you open the account, and the funds must be used for a first property purchase or accessed in retirement after age 60. Withdrawing for any other reason triggers a 25% penalty charge. Interactive Investor does not currently offer a Lifetime ISA — if this account type is part of your savings plan, AJ Bell is the only option between these two platforms.
Which broker is better for ETF investors?
Neither platform offers commission-free ETF trading — both charge the same commission rate for ETFs as for shares. For passive ETF investors using regular automated contributions, ii’s free regular investing on all plans is a meaningful advantage: AJ Bell charges £1.50 per automated order, which adds up to £18/year at monthly frequency — fully offsetting AJ Bell’s single-ISA custody advantage. For multi-account ETF investors, ii wins on total annual cost in most scenarios. Neither broker is limiting in terms of ETF selection for a core UCITS portfolio.
QuantRoutine provides educational content only. Nothing on this page is an offer, solicitation, or recommendation to buy or sell any security or to open an account with any specific broker. Fee data reflects publicly available information as of May 2026, including Interactive Investor’s post-February 2026 plan restructure. Fees change — always verify current charges on each broker’s official website before opening or funding an account. Cost scenarios are illustrative estimates based on stated fee schedules and assumed trading patterns; actual costs will vary. Investments can lose value and past performance does not guarantee future results. You are responsible for your own investment, tax, and legal decisions.