Bitcoin Forum

Is there any way to recover BTC if you suddenly lost it without knowing the reason?

Recover from where? If you mean Coinbase, probably.

If it is just a wallet and you don't know where the private key is.... no. But we need details.

This is why it's entirely out of the purview for taxation (despite claims) prior to conversion to fiat. No one can ever help you whether it was $10 or $10b.

Less detail better to share with us if you are are using web wallet or you are using a wallet like electrum..
Because if you lose private keys and seeds you will never recover it back again..
But according to your question i think you are talking about a lose bitcoin not recovering a wallet. i think if you lose your bitcoin you and forgot where you save your bitcoin.. better try your self to check 1 by 1 if what wallet your are using . or if your bitcoin is in paper wallet and its gone. its impossible to recover your bitcoin back..

You had coins on an address and now it's empty, right? If you haven't used the coins then somebody else did and that person either has access to a device that holds your wallet or you've shown your private key to someone or pasted it somewhere by mistake. If someone emptied your address your coins are beyond recovery, unless you find out who it was.

You have asked this question in the legal board, so I assume you have lost your coins to somebody else.
If you take the legal route, unless your police officer is knowledgeable about bitcoins, you are going to have a tough time explaining things to him.

It is possible now that the legal proceedings for bitcoin crime have not been able to fully get a good settlement in the way we all expect. If the case is in an illegal place bitcoin, I think it is rather difficult to get legal protection assistance from the authorities.

Bitcoin is nothing physical that it can fall of your pant while you were cycling. It is stored in wallets. If by lost you meant losing the wallet, yes, you can recover them, but you have to have the private key of your addresses or the seed, which is a set of key phrases of your wallet. That is the reason we need to keep the wallet seed and the private keys noted somewhere we will never lose.

Maybe this is a funny question, but it could happen after 20 years. BTC is hard to break down unless regulation in the world prohibits BTC circulation. it's impossible

You are going to need to go into far more detail.

We need to know the events which unfolded that led to you losing Bitcoin, among other things.

Which address was it sent to? How did you lose it? Was it on an online wallet? Your local PC/laptop? Paper wallet? Did you have a backup? There are too many variables involved.