I recently had to go to Tanzania with $25,000 in cash for some business we were doing there. I met a container there that we had shipped from Dubai, cleared it through customs in Zanzibar and sold the contents over the course of the next week or so, all cash transactions. I came back to the states with a little over $45,000 in cash, which I declared on the form coming back into the US.

No-one questioned me or asked me anything about the cash and I never thought anything of it. Based on what happened in this story, do I run the risk of having funds over $10K confiscated whether I declare them or not?

Especially in my case as there really isn't documentation I could carry, other than a bank statement showing $25K being withdrawn and maybe all the paperwork showing what we paid in import taxes etc.