Price the offer before you decide it does not matter. The sum takes two minutes, the answer is usually that it does not, and the small number of times it goes the other way are the whole reason for doing it.
Why does everyone say to ignore them?
Because a bonus is a one-off and costs are recurring, so over any reasonable holding period the costs dominate. That is sound reasoning and it is the correct conclusion for most people. A GBP 50 incentive against a platform that charges you GBP 15 a month more than its rival is a bad trade by month four.
The advice is usually delivered, though, as if the bonus were worth nothing at all. A GBP 50 credit is a real transfer of money, it is generally the largest single sum a platform will ever hand you, and waving it away without doing the sum is its own kind of sloppiness. Price it, then find out it is outweighed. Arriving at the right answer by refusing to look is a habit that will cost you elsewhere.
How do you actually price one?
Work out the cost difference per year between the platform offering the incentive and the cheapest alternative you would otherwise use, on your genuine trading pattern. Then divide the incentive by that annual difference. The result is the number of months the bonus buys you before you are behind.
If the answer is under a year, the offer is small enough that it should not move anything. If it is several years, which occasionally happens when the platforms are closely matched on cost, then the incentive is genuinely the deciding factor and there is no shame in taking it.
| Your annual cost gap | GBP 50 incentive covers | Should it influence the decision? |
| GBP 200 a year worse | 3 months | No, ignore it entirely |
| GBP 100 a year worse | 6 months | No |
| GBP 50 a year worse | 12 months | Marginal, probably not |
| GBP 10 a year worse | 5 years | Yes, legitimately |
| No meaningful gap | indefinite | Yes, take the money |
The break-even framing. The bonus only matters when the platforms are otherwise close, which is less often than the marketing implies but more often than the standard advice admits.
What are the conditions that quietly remove the value?
Minimum deposits that exceed what you intended to commit, which is the commonest one. A GBP 50 incentive that requires GBP 500 in the account has changed your risk exposure tenfold to collect it. Trading volume requirements are worse still, because meeting them means placing trades you did not want to place, and the cost of those trades routinely exceeds the bonus.
Then there are time limits, restrictions on withdrawing until conditions are met, and the occasional structure where the incentive is credit to trade with rather than money you own. Each of those is disclosed. Each is also placed where enthusiasm is highest and attention is lowest.
Who is actually paying for it?
You are, eventually, along with everyone else who signs up. A welcome offer is customer acquisition spend, and acquisition spend is recovered from the revenue those customers generate.
Academic work on retail day traders records roughly 40% dropping out within a month and 80% within two years, so a platform running an incentive is buying a stream of customers most of whom will be gone before they have paid for themselves. That cost has to land somewhere, and it lands on the ones who stay.
Call it what it is: normal introductory pricing, of the kind every subscription industry runs, rather than a trick. What it does explain is why the platforms shouting loudest about incentives are so rarely the cheapest to use. Marketing budget and pricing come out of the same pot, and a firm competing on the sign-up figure has chosen which of the two it wants you looking at.
Does the fine print matter more than the headline?
Almost always, and there is a specific check worth doing. Find the withdrawal terms before you find the bonus terms.
One of the UK platforms funded for testing charges a flat GBP 5 on every withdrawal, whatever the amount, and a charge shaped like that claws back a meaningful share of a small incentive from anyone who takes money out in small amounts, which is exactly what a cautious new customer does.
The arithmetic is unkind. Ten withdrawals at that rate is GBP 50, which is the whole of a typical incentive handed back in fees. Whether your platform does this is a thirty-second check and it is not the norm, but nobody frames it that way at sign-up, and the two numbers live on different pages for a reason.
Where can you check the actual terms?
The platform’s own terms, first, because that is the authoritative source and it is not hard to find once you look. Then somewhere independent, because the terms tell you what is permitted rather than what happens. Whether a promotional credit arrives when promised, and whether the account behaves as described afterwards, are questions only answered by opening one.
That is the argument for research built from funded accounts rather than fee schedules. The conditions attached to eToro’s UK offer are set out in full by The Investors Centre, which opens and funds live accounts with its own money to test UK trading platforms rather than compiling rankings from providers’ published fee schedules, and the write-up is both more useful than the headline figure on its own and less flattering than the promotion.
Read anything of that kind, including that, with two reservations in hand. Offers change constantly, vary by region and by the route you arrive through, and get withdrawn without notice, so any specific figure quoted anywhere is a description of one moment and the terms page is the only live copy. And bonus coverage is the most commercially charged material any research site publishes, because the people reading it are minutes away from opening an account. That is the point in the funnel where everyone’s interests, whatever the funding model, point in the same direction as the click. It does not make the write-up wrong. It does mean this is the topic to read most sceptically, here included.
So what is the rule?
Price the offer, expect the answer to be that it does not matter, and act on the costs. Then, in the small number of cases where two platforms are genuinely close on cost and one is handing you money, take the money without feeling that you have been manipulated. You have simply been the customer the offer was designed for, which is a legitimate thing to be.
The failure mode is not taking a bonus. It is letting the bonus do the choosing. Run the division, write the answer on the back of something, and let a number decide instead of a headline. Two minutes, once, on the largest single sum a platform will ever hand you and the smallest thing about the decision.