Side note: I see this kind of response a lot on HN. Whenever a precisely-defined law or regulation comes up, there will be the inevitable tricksy engineers pointing out a bug in the program. Except they haven't read the whole program, but only a couple of stanzas. And it's not actually a program. It's not being interpreted by a computer, but by people. At a certain point, rules-laywering will get the actual lawyers to tell you to get out of here with that.
Repeating something I've written here before: Your adversaries are people, not bash scripts.
$10k is just the automatic threshold for a CTR. A $1 transaction could cause a SAR to be filed, if there was a reason for the bank to be suspicious of it.
In a lot of countries if you establish a small company and open a bank account for it they will just do the bare minimum, after all if you got a tax number and just got a new company registered you already jumped through a few background check hoops.
Of course they will still run your name through their whatever systems. And eventually if your business starts transacting it'll be constantly looked at by the automated systems.
As long as you don't do anything suspicious, no one will care.
Basically if you behave like all the small shops that have to deposit cash, no one will look twice.
Also, cash is not interesting, the problem is when you start to wire money (or get transfers) to/from places that small kitchens usually don't. And that's when risk and compliance departments might notice the activity.
No, the bank doesn't ask for receipts or stake out businesses.
If that business has a transaction profile that's out of line with the 'similar business' model, they potentially get flagged.
* make sure the deposits are under $9000, but also not some amount that's "suspicious" like $8,999
* make sure the deposits happen on a regular interval
* make sure the deposits are at the same branch
I also suspect banks don't share information to generate SAR (eg. a deposit of $15,000 at one bank would generate a SAR, but a deposit of $7,500 at two banks on the same day won't generate a SAR), so if you need to deposit more cash then all you need to do is open more accounts at more banks.