Yes. And most importantly, you can laugh the users. See my post at the very top. Only very few countries know which phones numbers belong to whom. In many countries such data is only with the telecom companies. How can they match anything?
As mentioned initially, in most countries what you ask for us done manually. Take Switzerland, the tax audit works on a village level. Not cantons, villages with 5000 residents. No, they do not invest in but AI. Also, the country works in self declaration, you can decide to not declare your Swiss bank account. They won't notice until the guy thinks that your︀ money went down more than what you can spend.
Belgium, Luxembourg, Austria, etc. All it︁ similar size. It is small and investments in AI simply do not pay off that︂ fast like on the US or UK.
And even the notorious Germany works, as
@BarleyMalt mentioned mainly from denunciations.
@Martin Everson the fake number test was in many newspapers in︃ early 2000's, but the usefulness is limited.. On a personal declaration, there aren't many numbers︄ and many things have set caps or hand given market value like a salary with︅ a given distribution. For business in B2C, it won't work either as a restaurant or︆ a supper market has a clear spend distribution, limited by the cheapest item and the︇ amount you can carry out eat. Most McDonald's bills are the value of one menu︈ times the number of people eating. It is however useful for B2B where there is︉ a big variation of how much you can order. Take a graph with logarithmic axis︊ and see how big the junk between 1 and 2 is compete to the rest,︋ that's hot often you should have a number with 1 first. But is you were︌ to fake it, would you really write RAND(1, 999999)? At least when looking at the︍ result, you should see that you have to many big orders.