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.
Index fund investors who want the lowest possible total cost and are comfortable with a newer app.
Beginners building a habit, and first-time buyers using the Lifetime ISA.
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.
Early 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 TrustpilotUsers love the round-ups, the goal-based design and how painless it makes starting. 93% of customers surveyed in 2026 would recommend it.
The £1 monthly subscription on top of the platform fee is often flagged as expensive for balances under £5,000.
Read Moneybox reviews on Trustpilot| Fee | Prosper | Moneybox |
|---|---|---|
| Platform fee | £0 | £1/month subscription (waived at £5,000+) plus 0.15% to 0.45% platform fee |
| Share dealing | Not applicable (funds and ETFs) | US stocks available, 0.45% FX fee |
| Fund dealing | Free | Free (fund fees apply) |
| FX fee | None on GBP fund classes | 0.45% on US stocks |
| Stocks & Shares ISA | Free | Subscription plus 0.15% on Moneybox funds or 0.45% on other funds |
| SIPP | Free | 0.45% on the first £100k then 0.15% (other funds); 0.15% capped at £150 a year (Moneybox funds); no subscription |
| Withdrawals | Free | Free |
| Minimum to start | No minimum | £1 |
A 0.25% yearly fee gap sounds small. On £50,000 over 20 years it is about £5,900 (illustrative). Add your ISA and pension balances to Delphina yourself and see what your charges cost by retirement and whether you're on track.
See what my fees costIllustrative: £50,000, 5% a year growth before charges, 0.25% vs 0.50% a year in charges, no further contributions. Not a recommendation of Prosper or Moneybox. Delphina is guidance, not financial advice.
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.
Moneybox is designed for getting started. Round-ups, weekly deposits and simple starter portfolios remove the friction that stops most people investing, and its Lifetime ISA is one of the most popular routes to a first home deposit.
The convenience has a cost on small balances: £1 a month plus up to 0.45% is one of the higher fee stacks here below £5,000 in non-Moneybox funds. The subscription drops away at £5,000, and Moneybox's own funds carry 0.15% rather than 0.45%, so the total depends on your pot size and fund choice.
It depends on what you hold and how often you trade. Prosper's platform fee is £0, against £1/month subscription (waived at £5,000+) plus 0.15% to 0.45% platform fee at Moneybox. On dealing, Prosper charges not applicable (funds and ETFs) for shares and free for funds, while Moneybox charges US stocks available, 0.45% FX fee for shares and free (fund fees apply) for funds. Fees verified July 2026.
Prosper is best for index fund investors who want the lowest possible total cost and are comfortable with a newer app. Moneybox is best for beginners building a habit, and first-time buyers using the Lifetime ISA. Both are FCA regulated and covered by the FSCS.
On Prosper's ISA: Free. On Moneybox's ISA: Subscription plus 0.15% on Moneybox funds or 0.45% on other funds. Prosper offers a flexible ISA and Moneybox does not. Minimums are No minimum at Prosper and £1 at Moneybox.
Prosper offers a SIPP (free). Moneybox does not offer a SIPP.
Prosper scores 4.6 out of 5 on Trustpilot (Excellent) from around 300 reviews. Moneybox scores 4.4 out of 5 (Excellent) from around 4,800 reviews. The review base is small and some users want more account types and a web version. The £1 monthly subscription on top of the platform fee is often flagged as expensive for balances under £5,000.
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. Prosper charges free on withdrawals and Moneybox 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.
Prosper or Moneybox, 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.