As I understand it, the way the IRS is structured, if you take in money from any source (documented or not, legal or not), that counts as “income” unless there is an explicit rule saying it does not, and they want their cut.
But, like anything else they do, they only care about significant amounts. If you find a $1 bill (or even a $100 bill) on the ground, nobody is going to audit you over it. But, if $10k drops out of the back of a truck into your lap, and they find out about it, you might expect some uncomfortable questions.
How would they find out? Well, banks are required to report large cash deposits and withdrawals. So if you show up with an extra $40k one day and put it into the bank all at once, the teller may ask you why, and report whatever your answer is to the government. (And if you space it out over 40 deposits of $1k, that is also suspicious and may be illegal if the authorities determine you were doing it specifically to avoid reporting).
Historically, this has been a way to get at organized crime syndicates. Al Capone was a famous mobster who ultimately went to jail bit because of his illegal activities, but because of evading taxes owed on them.
As I understand it, the way the IRS is structured, if you take in money from any source (documented or not, legal or not), that counts as “income” unless there is an explicit rule saying it does not, and they want their cut.
But, like anything else they do, they only care about significant amounts. If you find a $1 bill (or even a $100 bill) on the ground, nobody is going to audit you over it. But, if $10k drops out of the back of a truck into your lap, and they find out about it, you might expect some uncomfortable questions.
How would they find out? Well, banks are required to report large cash deposits and withdrawals. So if you show up with an extra $40k one day and put it into the bank all at once, the teller may ask you why, and report whatever your answer is to the government. (And if you space it out over 40 deposits of $1k, that is also suspicious and may be illegal if the authorities determine you were doing it specifically to avoid reporting).
Historically, this has been a way to get at organized crime syndicates. Al Capone was a famous mobster who ultimately went to jail bit because of his illegal activities, but because of evading taxes owed on them.