Phase out the old currency, and give you a time limit to trade it in for the new. Currency exchange records would be kept, and compared to tax records, etc.
Silver and gold.
“So how are they going to track what I have in my mattress?
Phase out the old currency, and give you a time limit to trade it in for the new. Currency exchange records would be kept, and compared to tax records, etc.”
Gold, silver, and bullets.