Freelancing working company based in Europe

Be very careful what your visa says. If it says no working or not permitted to work it means just that. No work at home also. You can however invest and use your proceeds as income. Whatever you decide you must report any digital income to the Inland revenue. Electronic banking is tightly controlled and bringing in big money is closely monitor cos of anti-money laundry laws. You will be interviewed each time the amount exceeds 500-quid. I currently bank with RHB and use their paypal services. It is fast and convenient as long as the funds don't exceed $100.  Paypal will provide you with a history of transactions for your tax records if you have a merchant account.

You cannot work on a spouse visa of it is not endorsed to work. The work you do is taxable in Malaysia.

Chance of getting caught? Low. What if you get caught? Fines and deportation,  never can come back.

Safest bet is to set up a local company with your wife and pay taxes via that route.

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