Worked example
Is Wise halal?
Search this and you will find confident answers in both directions. That is not because the sources are unreliable — it is because they are answering two different questions.
Wise charges an explicit service fee and displays the exchange rate before you confirm. On the majority view reported in Islamic-finance commentary, a clearly disclosed charge for a currency-conversion service is permissible, with disclosure being the material point. Wise's fee transparency is, if anything, the aspect most often cited favourably.
A different assessment entirely. Shariah stock screens examine a company's balance sheet — interest-bearing assets and debts, income sources, business activities. Screening bodies including Musaffa and Muslim Xchange have assessed Wise plc as not compliant for investment purposes.
Why both can be true at once
A financial company can hold interest-bearing assets on its own balance sheet — which is what typically causes it to fail a stock screen — while the specific service it sells you does not itself involve you in an interest-bearing contract. Buying a coffee from a company that finances itself with debt is not usually treated as participating in that debt. The same logic separates using a payments service from owning the payments company.
That is the resolution to the contradictory search results: the screening verdict is real, accurate, and about something other than what most people asking the question mean.
What to actually check
If your concern is the transfer itself, the structural questions set out in what makes a transfer a compliance question are the relevant ones: is the rate disclosed before you commit, and is the exchange simultaneous rather than deferred.