Both are FCA-regulated and FSCS-protected. The real difference is fees, account types and how each platform feels to use. Verified against each provider’s published charges.
Fees verified July 2026. Capital at risk. Information, not financial advice.
Fund investors who value guidance, tools and phone support.
Index fund investors who want the lowest possible total cost and are comfortable with a newer app.
Tick what you need. No account, no email. The answer is on this page.
Tick what you need above and we'll tell you which of the two covers it.
Account availability verified July 2026. Capital at risk. Information, not financial advice.
Reviewers highlight helpful phone support and a straightforward transfer process.
The £7.50 share dealing charge and dated parts of the website draw criticism.
Read Fidelity reviews on TrustpilotEarly adopters praise the zero fees and responsive founding team; roughly 84% of reviews are five stars.
The review base is small and some users want more account types and a web version.
Read Prosper reviews on Trustpilot| Fee | Fidelity | Prosper |
|---|---|---|
| Platform fee | 0.35% up to £250k (0.20% above); £90/year flat if under £25k without a regular savings plan | £0 |
| Share dealing | £7.50 per online trade | Not applicable (funds and ETFs) |
| Fund dealing | Free | Free |
| FX fee | 0.75% tiered | None on GBP fund classes |
| Stocks & Shares ISA | Platform fee applies | Free |
| SIPP | Platform fee applies | Free |
| Withdrawals | Free | Free |
| Minimum to start | £25/month or £1,000 lump sum | No minimum |
Fidelity is a solid full-service choice for fund investors. Fund dealing is free, the ETF and share service fee is capped at £90 a year, and the guidance content is some of the best of the big platforms.
Costs are less friendly if you trade shares often or hold a small account without a regular savings plan. Compare it against AJ Bell if you want similar breadth with lower dealing charges.
Prosper's pitch is the cheapest total cost of ownership in the UK: no platform fee, no dealing fees, and refunded fund fees on a list of mainstream index funds. For a straightforward global tracker in an ISA or SIPP, the all-in cost really can be zero.
The counterweight is maturity. It is a young platform with a small (if very positive) review base and no individual shares. If that trade-off suits you, the price is unbeatable.
It depends on what you hold and how often you trade. Fidelity's platform fee is 0.35% up to £250k (0.20% above); £90/year flat if under £25k without a regular savings plan, against £0 at Prosper. On dealing, Fidelity charges £7.50 per online trade for shares and free for funds, while Prosper charges not applicable (funds and ETFs) for shares and free for funds. Fees verified July 2026.
Fidelity is best for fund investors who value guidance, tools and phone support. Prosper is best for index fund investors who want the lowest possible total cost and are comfortable with a newer app. Both are FCA regulated and covered by the FSCS.
On Fidelity's ISA: Platform fee applies. On Prosper's ISA: Free. Prosper offers a flexible ISA and Fidelity does not. Minimums are £25/month or £1,000 lump sum at Fidelity and No minimum at Prosper.
Fidelity offers a SIPP (platform fee applies). Prosper offers a SIPP (free).
Fidelity scores 4.6 out of 5 on Trustpilot (Excellent) from over 6,500 reviews. Prosper scores 4.6 out of 5 (Excellent) from around 300 reviews. The £7.50 share dealing charge and dated parts of the website draw criticism. The review base is small and some users want more account types and a web version.
Yes. UK platforms accept ISA and SIPP transfers in, and you start the transfer with the receiving provider rather than the one you are leaving. Fidelity charges free on withdrawals and Prosper charges free. Transfer as cash and you are out of the market while it settles; transfer in specie and you keep your holdings but it takes longer.
Fidelity or Prosper, the account is the easy part. What decides when you can retire is how much goes in and for how long. Delphina works that out from what you already hold and what you pay in each month.
Free to check. No card required. Takes about two minutes.