UK Robo-Advisor vs DIY Index Investing (2026/27)
UK robo-advisor vs DIY index investing 2026/27: what each approach charges for, what a 0.25% to 1.5% annual fee costs over 25 years, and ISA transfers.
What you pay for
| Approach | Charges | What you get |
|---|---|---|
| Managed service (robo-advisor) | Management or platform fee, plus the charges of the funds in the portfolio | Questionnaire sets a risk level; the provider picks the funds, invests contributions and rebalances. Some offer advice at extra cost. |
| DIY platform, single multi-asset index fund | Platform fee (percentage, flat, or both) plus the fund charge | One fund with a fixed or target mix of shares and bonds; the fund rebalances internally. |
| DIY platform, global equity index fund | Platform fee plus the fund charge | All-shares exposure in one fund; you decide whether to hold bonds or cash alongside it. |
| DIY platform, target-date fund | Platform fee plus the fund charge | Share/bond mix moves towards bonds as a chosen year approaches. |
Provider charges change and often depend on pot size, so check each provider's current published costs and charges and add them up in pounds for your own balance.
25-year compound cost impact
Starting balance £100,000, hypothetical 7% a year gross return, all-in charge taken from the pot each year, 25 years, no further contributions. Illustration only: real returns vary and can be negative.
- 0.25% a year: about £510k
- 0.5% a year: about £479k
- 0.75% a year: about £450k
- 1% a year: about £422k
- 1.5% a year: about £372k
The gap between a 0.25% and a 1.5% annual charge on the same £100,000 is about £137,857 over 25 years. Over longer periods or with regular contributions the gap grows.
Related guides
- UK S&S ISA Provider Comparison 2026/27 - platform-by-platform.
- UK SIPP vs Personal Pension 2026/27 - retirement wrapper.
- UK ISA Strategy Complete 2026/27 - holistic ISA plan.
- UK FIRE Movement 2026 - DIY index investing for FI.
Frequently asked questions
What's the cost difference over time?
Fees compound like returns do, in reverse. Illustration: £100,000 invested for 25 years with a hypothetical 7% a year gross return and the fee taken from the pot each year. At an all-in charge of 0.25% it ends at about £509,820; at 1.5% about £371,963, a difference of £137,857. With no charges at all it would be £542,743. Real returns vary and can be negative; the point is that the gap is driven by the fee difference and the time invested, both of which you can see in advance.
When does a robo-advisor justify the higher fee?
A managed service can be worth paying for if it is the difference between investing and not investing: for example if choosing funds would stop you starting, if you want rebalancing and contributions handled for you, or if you know you would be tempted to sell in a falling market and value a provider that keeps you to a plan. If you are comfortable picking one diversified fund and leaving it alone, a DIY platform with a low-cost fund usually costs less. Compare the total yearly charge in pounds at your pot size, not just the headline percentage.
What's the simplest DIY portfolio?
One fund. Either a global equity index fund (shares only, developed and emerging markets) or a multi-asset index fund with a fixed share/bond mix that matches the risk you are prepared to take. Choose accumulation units if you want income reinvested automatically, set up a regular contribution and review once a year. Holding one diversified fund removes the need to rebalance between funds; a multi-asset fund rebalances itself.
What about target-date retirement funds?
A target-date fund is linked to a year, usually when you expect to retire, and shifts from shares towards bonds as that year approaches. It suits people who want that change made for them inside one fund. The trade-off is that the glide path is the provider's, not yours: check how much it holds in shares at and after the target date, especially if you plan to keep the pot invested in drawdown rather than buy an annuity.
Which robo-advisor is best?
There is no single answer, and fees change, so this page does not rank providers. Compare: (1) the total annual cost at your pot size, combining the provider fee, the fund charges and any transaction costs, using each provider's published costs and charges; (2) the wrappers offered (Stocks and Shares ISA, Lifetime ISA, SIPP, Junior ISA); (3) the range of risk levels and any ethical options; (4) whether advice is included or extra; and (5) that the firm is FCA-authorised. FSCS protection of up to £85,000 per person per firm applies if an authorised investment firm fails and cannot return your assets; it does not cover investments falling in value (FSCS).
Can I switch from robo-advisor to DIY?
Yes. If the money is in an ISA, use the ISA transfer process: contact the provider you want to move to and complete its transfer form. If you withdraw the money yourself instead, paying it back in uses up that year's £20,000 allowance, unless the ISA is flexible and you replace the money in the same tax year (GOV.UK). Transfers other than cash ISA to cash ISA should take no longer than 30 calendar days. The receiving platform may not hold the same funds, so the transfer may be in cash, which leaves you out of the market for a few days; some providers charge exit fees, so check before you move.
What about active fund management?
Actively managed funds generally charge more than index funds, and that extra charge is certain while any outperformance is not. Whether active managers as a group beat their benchmarks after costs varies by market and period. If you use active funds, compare the total cost and judge the fund over a long period against an appropriate index, not against recent returns. For most long-term savers, a low-cost diversified index fund is a reasonable default.
How important is rebalancing?
Rebalancing keeps your mix of shares and bonds at the level of risk you chose; without it a portfolio drifts towards whatever has risen most. Managed services and multi-asset funds do it for you. If you hold several funds yourself, checking once a year, or when an allocation drifts a set amount from target, is usually enough. Inside an ISA or pension, selling to rebalance has no tax consequence; in a general investment account, sales can create Capital Gains Tax.