re: How much cash can you deposit without being flagged by IRS?

If you deposit 10k or more of cash, the bank has to generate a report to the IRS. Happens all the time. It doesn't mean you owe taxes on it or that it's illegal; it just gives the feds a way to sniff out drug dealers, tax cheats, and other criminals.

If you break it up into smaller deposits to avoid the report, that is called structuring. It is a federal felony, and people do go to the pen for it.

If the bank is suspicious because, say you often deposit 7k, they may send a report. You may have a very legit reason to do what you did, but if not it could spell trouble.