Do I need to be online to receive bitcoins

[jintau30]

I am using a bitcoin client and a wallet from it. What if I close the client? Will I still receive the bitcoins sent to my address?

[lile]

Yes, of course. It wouldn't be very convenient otherwise. You can even go one step further, print the private key to paper and delete it from your computer, and you would still be able to get to all bitcoins that would eventually appear on the address.

To clarify a bit, there is no such thing as "bitcoins being sent to an address", per se. Bitcoins are there for the taking by everyone who has the appropriate private key.

[Fjordbit]

I just want to expand a bit on lile's post so that you have a better understanding of this system. The tracking of your bitcoins in your address is done by everyone. The peer to peer network copies the coins out to every node, so the fact that they have their computer on is what records your coins. They are sitting out there in the system, and you can go see them at blockchain.info and other places without turning on your client.

What you client and your wallet allow you to do is spend the coins. You can't send out a transaction saying "give coins from X address to Y address" without your computer being on the internet and connected to other bitcoin nodes.

[odolvlobo]

No bitcoins are stored in wallets. Wallets contain the private keys that allow you to spend the bitcoins associated with those keys, nothing more. All bitcoins are stored in the block chain, though "stored" is not really the right word.

For example, here is how a paper wallet works: you generate a private key, and you print it on a piece of paper. That's it.

[jintau30]

Thanks a lot with a followup question.

I suppose I can have any number of private keys with coins in each address. Is that a standard practice - split up money into multiple wallets to reduce the risk of loss?

Also once I use the BTC in a wallet I can essentially disregard the private key right?

[odolvlobo]

I suppose I can have any number of private keys with coins in each address. Is that a standard practice - split up money into multiple wallets to reduce the risk of loss?

I don't think it is standard practice for most people to do that to reduce risk. Companies with a large amount of BTC do it to protect themselves because they are targets. However, you might have several wallets and several keys just for convenience.

Edit: removed some misleading information

[Foxpup]

Also once I use the BTC in a wallet I can essentially disregard the private key right?

You can, but most people maintain one or more keys for convenience. For example, the one in my signature is the first one I got, but I also have separate keys for receiving BTC from different sources, as a simple form of bookkeeping or to verify that a specific transaction took place. The hidden keys that your wallet uses are discarded when the money they contain has been transferred out.

Not true. The standard client never deletes previously used keys automatically under any circumstances and has no built-in way to do so manually, and with good reason. Once a key is deleted, if somebody sends coins to that address in the future, those coins effectively disappear forever, and there is no way to ever get them unless you happen to have a backup copy of the key lying around somewhere. And don't think that because an address is hidden in the client, nobody will ever try to send coins to you that way: a common (but dangerous, for unrelated reasons) method of performing a refund is to send the coins back to the address they came from. If you've deleted the key to that address, then your coins are gone forever. Don't even think about trying to delete private keys from your wallet without a damn good reason. Nothing good will come of it.

[mpx]

I am using a bitcoin client and a wallet from it. What if I close the client? Will I still receive the bitcoins sent to my address?

yes you'll 'receive' them, they'll sit in the blockchain allocated to your address until the private key from your wallet is used to move them. Don't delete your private key, of course...

[Gabi]

in b4 "do i need to be online to receive email?"

[Fjordbit]

in b4 "do i need to be online to receive email?"

This isn't really a fair comparison, because bitcoin is peer to peer and email is client-server. To receive email, the SMTP server that is associated to your email domain does need to be running. For bitcoin, the entire network would have to be down before coins couldn't be sent.

[Dabs]

They are similar, in the sense that the bitcoin network (nodes) are the server. For email, it is centralized to whatever you are using, such as yahoo or google or your local ISP.

For all practical purposes, you will receive email where ever you are, but you won't read it until you open it. Same with bitcoins, but you can't spend them until your client gives the instructions to the other nodes (or is online.)

The client and the other nodes do some checking, so you can't spend what you don't have.