1
InvestEngineBest pick
A 0% platform fee and 0% dealing fees on DIY portfolios, with AutoInvest for automated regular contributions — a regular ETF investing plan loses nothing to platform costs.
2
Trading 212
0% platform fee and 0% commission, with AutoInvest and Pies for structured regular investing. The only real cost is a 0.15% FX fee on non-GBP holdings.
3
interactive investor
The flat monthly fee doesn't scale with your deposit size, so it becomes progressively better value the more you invest each month — but it's a fixed cost for very small regular deposits.
How we chose
For a regular investing plan, we prioritised a genuinely free (or flat, predictable) cost structure and strong automation tools for recurring contributions. Hargreaves Lansdown is a capable option for regular investing too — fund dealing is free via regular investing, and shares can be bought this way as well — but its overall cost structure keeps it outside the podium for this specific, cost-focused ranking; the full review covers where it fits.
Frequently asked questions
Is a fixed custody fee ever worth it for regular investing?
Yes, if your deposit amounts are high enough to make the fixed fee proportionally small — below a certain monthly deposit threshold, a broker with no fixed fee but a per-order commission is nearly always more cost-effective.
Is it better to invest monthly or make less frequent, larger deposits?
It also depends on the cost structure of your chosen broker: with a 0%-fee broker like InvestEngine or Trading 212, deposit frequency matters much less than with a broker charging a fixed monthly subscription.