Both are FCA regulated and FSCS protected. The real differences are fees, investment range and how each platform feels to use. Here is the honest comparison.
Fees verified July 2026. Capital at risk. Information, not financial advice.
Investors who want funds and shares on one platform without paying Hargreaves Lansdown prices.
Portfolios above roughly £60k where a flat fee beats percentage charges.
| Fee | AJ Bell | Interactive Investor |
|---|---|---|
| Platform fee | 0.25% on funds up to £250k (tiered lower above); shares capped at £3.50/month in an ISA and £10/month in a SIPP | Core £5.99/month (up to £100k); Plus £14.99/month (no limit); Premium £39.99/month |
| Share dealing | £5.00 per trade | £3.99 per trade (£2.99 on Premium) |
| Fund dealing | £1.50 per trade | £3.99 per trade (£2.99 on Premium) |
| FX fee | 0.75% on the first £10k, tiered lower above | 1.5% on the first £25k, tiered lower above |
| Stocks & Shares ISA | Platform fee applies, no separate ISA charge | Included in the monthly plan |
| SIPP | Platform fee applies, capped at £120/year for shares | Included in the monthly plan |
| Withdrawals | Free | Free |
| Minimum to start | £25/month or £500 lump sum | No minimum (£25/month for regular investing) |
Reviewers repeatedly mention that the platform is easy to use and communication is clear. AJ Bell has been Which? Recommended for eight years running.
Occasional gripes about transfer times and the dealing charge compared with app-only rivals.
Read AJ Bell reviews on TrustpilotLong-standing customers value the flat fee and the breadth of investments.
The 1.5% headline FX fee and occasional platform outages are the recurring complaints.
Read Interactive Investor reviews on TrustpilotAJ Bell sits in the sweet spot between cheap app-only brokers and expensive full-service platforms. You get funds, shares, ETFs, a well-regarded SIPP and a Lifetime ISA, with caps that keep costs sensible for share investors.
It suits people who want one account for everything, particularly ETF investors who benefit from the £3.50 monthly cap in an ISA. Fund-heavy portfolios above six figures should compare the 0.25% fee against a flat-fee platform like Interactive Investor.
Interactive Investor charges a flat monthly subscription instead of a percentage. On a £200,000 portfolio, £5.99 a month is a fraction of what percentage-fee platforms charge, which is why ii keeps winning larger DIY investors.
The equation flips for small pots: £71.88 a year on £10,000 is 0.7%, more than almost any rival. Work out your portfolio size first, then decide.
A 0.2% fee difference is worth optimising. Knowing whether you are saving enough in the first place is worth far more. Delphina models your pensions, ISAs and investments and tells you where you actually stand.