If you’ve dipped a toe into investing over the past few years, chances are you did it through an app that promised to be free. No commission, no fuss, money growing while you get on with life. It’s a lovely idea, and to be fair, investing has never been cheaper or easier to start. But free is doing quite a lot of heavy lifting in those adverts, and a few quiet charges can add up to real money over the years.

 

Where the money actually goes

Investing apps are businesses, and they earn from the bits that don’t make the marketing. There’s the spread, which is a small gap between the price you pay for a share and the price you’d get selling it back. There are currency conversion fees, typically 0.5 to 1.5 percent, every time you buy American shares, which is most of the popular ones. Some apps charge monthly subscriptions, some charge you to withdraw your own money, and some charge an inactivity fee if you leave your account alone, which feels a bit like being fined for being sensible.

None of these charges is scandalous on its own. The point is the pattern. UK trading statistics compiled from FCA data and the platforms’ own company filings show that the average active customer is worth thousands of pounds a year in revenue to the big trading apps. That revenue comes out of ordinary people’s pockets, mostly without anyone noticing a single charge.

 

The £200-a-year difference nobody checks

Here’s the bit that genuinely surprises people: two households making exactly the same investments on different apps can end up with very different bills. A regular habit of putting £100 or £200 a month into US shares might cost pennies on one platform and £15 or more each month in conversion fees on another. Over a year that’s the cost of a weekend away. Over twenty years of steady investing, it quietly eats a chunk of the nest egg you were building.

And unlike the ups and downs of the stock market, which nobody controls, this cost is entirely optional. You just have to pick the right app for the way you invest.

 

A one-evening job that pays for itself

The good news is that comparing platforms properly is now easy, because independent reviewers open real accounts with real money and publish what things actually cost in practice. If someone in your house has caught the more active trading bug, a day trading platform comparison sets the regulated UK options side by side on all the fees that matter, including the ones the adverts skip.

Research sites such as The Investors Centre test these platforms with their own deposits, and their consistent finding is reassuringly boring: the difference between a well-chosen and a badly-chosen platform is usually worth more than any clever investment tip. Boring, but it’s the kind of boring that pays for the Christmas food shop.

 

Three quick checks before you tap ‘deposit’

First, look up the currency conversion fee if you plan to buy American shares, because for most casual investors it’s the biggest cost of all. Second, check what it costs to withdraw your money or to leave the account dormant, since life happens and accounts get forgotten. Third, if anyone is tempted by the racier leveraged products, read the risk warning that regulated providers must display. It states plainly what percentage of their own customers lose money, and it deserves thirty seconds of your attention before any deposit.

Investing is one of the best habits a household can build, and the apps have genuinely made it accessible to everyone. Just remember that free is a marketing word, not an accounting one, and ten minutes of comparison now can save you hundreds of pounds down the line.