You can use decentralized exchanges like Bisq (https://bisq.network/) which basically connect peers that want to exchange Bitcoin for fiat and have some clever mechanisms to ensure none of the parties can cheat. The BTC you receive is not associated to your identity and on the fiat side the bank just sees an outgoing transaction to another bank account and can’t tell it is to buy Bitcoin, so that’s one of the best ways to acquire Bitcoin anonymously. Liquidity may be a problem though, for instance you may only find offers to sell a certain quantity of BTC or at a bit of a premium compared to a centralised exchange. You can also try Robosats (https://learn.robosats.com/).

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