system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why does illegal money need to be "laundered"?

for example, in breaking bad walt needs to have his meth money laundered as to not bring suspicion, but if he walks into a store and buys something with the cash, how would anyone ever know the money was meth money and how would he ever get caught?
gpt
Because people have to pay taxes, and the government would notice huge amounts of money appearing from nowhere.

Let's say that you are a drug dealer. You make cash money, and you buy a big house and a car. But, you don't pay any taxes. The IRS sees all of the sales records (the person that sold you the house files taxes, the dealership that sold you the car, etc.) and says "That's odd, this guy isn't reporting his income!" And then they investigate, and find out that you have all this illegal income, and you get arrested for not paying taxes, and then that gives them cause to look into everything else you have been doing.

Let's say, however, that you own a carwash. You get money coming in from that. But, you also have money coming in from your drug business. So, you make it *look* like the drug money was actually from cars in your car wash. The IRS looks at it and says "what a successful car wash," stamps your form, and you're good to go. It disguises the illegitimate money to look legitimate.