Fiat - it depends on the exact nature of services you plan to offer, but you'll likely need a Payment Institution license under PSD2 for currency conversion (usually clause 6, Money Remittance). PSD2 is an EU directive so once you get a license in for example France, you can passport the license across the EU and EEA. What will happen with UK due to Brexit is uncertain but everything points to financial services being largely unaffected.
You'll need at least 50,000 EUR but realistically more like 100,000 EUR to get the license, plus costs of running and operating the business.
Crypto - Estonia or Malta are the only EU jurisdictions regulating crypto exchanges right now.
In either case, start by approaching a knowledgeable law firm to guide you through the process.
Yeah he needs to define what he means by currency exchange.
If he means basic bureau de Change in UK then nothing really. Just register with HMRC and undergo a fit and proper check and away you go. Costs only £300. Everybody from Kebab shops to News Agents offer currency exchange last time I visited UK.
It is for currency conversion. The UK is not important but would be nice to be able to operate there if required also the cost of £300 sounds quite attractive.
I would like to set up in France.
Sols you put "You'll need at least 50,000 EUR but realistically more like 100,000 EUR to get the license, plus costs of running and operating the business." if this is to prove we have the funds to operate that is fine but if that is the fee for getting a license then it would be too much to pay for what I have in mind.