CompareStockISA

Interactive Investor Plus vs Prosper

Side-by-side comparison from each platform's published fees.

Interactive Investor Stock ISA Plus compared with Prosper Stock ISA

Interactive Investor

Stock ISA Plus

Prosper

Stock ISA
Estimated yearly costexample investor£224.88Not shown: it can't hold the example mix (see what it can hold)
Fees
Platform fee
Whole portfolio
Flat fee: £179.88 per year
Whole portfolio
No platform fees
Dealing
Shares and ETFs
£3.99 per trade, with a £3.99 trading credit each month
Mutual funds
£1.49 per trade
US shares and ETFs
£3.99 per trade
ETFs
£0 per trade
Mutual funds
£0 per trade
US shares and ETFs
Not supported
FX
Marginal:0.75% on £0-£49,9990.25% on £50,000+
No FX fees (UK only)
How trades are placedQuote & DealBatch Dealing
What it can hold
UK investmentsSupportedSupported
US sharesSupportedNot supported
Individual sharesSupportedNot supported
Exchange-traded funds (ETFs)SupportedSupported
Mutual fundsSupportedSupported
Flexible ISANot supportedSupported
Fractional tradingNot supportedSupported
About the providers
Official websiteVisit Interactive Investor websiteVisit Prosper website
Founded1987 (39 years old)2019 (7 years old)

Example investor: £80,000 portfolio, 12 trades a year, half in shares (half of them US) and half in UK ETFs. Estimate with your numbers

Important notice. The information shown on this page is sourced from provider websites and is for illustrative purposes only. It may be inaccurate, outdated, or not account for all scenarios, promotions, discounts, or variations in fees due to specific circumstances. Always check the provider's official website for the most up-to-date and accurate information. These figures are general estimates and should not be considered as financial advice. Data updated 8th October 2026.

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Use our illustrative calculator to estimate platform fees based on how you invest. Not financial advice.