Bitcoin Forum

Say your running a service that has a maximum fee and for legal reasons you can not accept more?  Can you easily send back an overpayment?

What about if your a charity and some undesirables donate via btc?  Are you able to send the money back?

You would have to set it up so that you have a unique address for each person for sending to you and they would have to give your their address for returns.

I never understood this. If some undesirable person gave you money for YOUR charity, isn't that kind of a good thing as now they have less money to do their undesirable things?

I know. Even taking someone's money associates you with that person. I just wish more looked at it as- "great, take the money, put it to better use!"

I agree with you...but it can raise negative political implications which could affect your charity overall.

Bad guy gives you money....other good people are influenced not to give you money...

logically it does not make sense...but people are not always logical.

So the answer is?  No?

As an example here is a listed transaction
https://i.imgur.com/SsvOy.jpg

Can't you just send back to the address?  or is that my address?

You can not send back to the sender UNLESS you are sure they didn't use a shared wallet such as mybitcoin. If they used Bitcoin on their computer then you can send it back. But unless you ask them, you have no way of knowing.

Why? You can make a unique address for each person sending money. When you give them the unique address get theirs at the same time.

EDIT: looks like its mine this is a huge problem.
Political donations, salary cap, conflict of interest.  I can think of many scenarios where this is an issue.

Financial services...for example in Australia you can run financial services related to non cash payments but once you get over a certain threshold you need proper regulatory approval. There is no way to impose a limit on the amount of money people send you.

Yes there is. Don't give them your Bitcoin address until they supply you theirs. Then if it's overpaid return some money. You could also in this step have them fill out name etc and keep track of all this in a database on your computer. All money would then be able to go back if needed and you could pick who you are returning it to.

Hmm I guess thats the only way thanks for the input!

As a newcomer I guess I fall into the same trap that most newcomers suffer.  I keep turning over the concept of bitcoins in my head looking for flaws...but greater minds than mine have already covered this ground.

More like bitcoiners discuss bitcoin for nine month straight, trying to look for problems in the system.

You can always find out where the coins came from and send them back there again.

Try putting an address in http://blockexplorer.com/

Although I don't think the standard client provides any way to make sure you send back from the address you received on.
Which you probably want to do unless you can prove the other addresses you use are related.

It's not safe to refund in that way.

Sheesh, talk about trying to create a problem where there isn't one!

If you don't know the sender's receiving address, just refund the coins to
1HqTdoMWtxZdbRb3awQDHykCWCPrJjKFyz

Treat it the same way as receiving "too much" cash in the mail from an anonymous sender.

I'm not a lawyer, so I'm not sure what the legally correct reaction would be in this case.  Destroy the money? Put it in a safe until the situation is clarified? Hand it over to the authorities?    Either way, you can do the electronic equivalent of all those things with Bitcoins too.

rotfl

What is the problem with doing it like that?

The problem is your not sure the person who sent you the money actually controls the address in question. It could be an address from a shared wallet (like MyBitcoin or MtGox...)

Thanks for the reply.

But, why is that my (as the rejector) problem?
If a donor has sent me some coins, from an address they control in some way, why is that any of my concern if they are using a proxy or not? Surely it is up to the proxy to maintain it's own refund procedures. Once I've returned the money to where it came from the issue is between the donor and the proxy and not me.

Bitcoin transactions in general do not have a from address. You may derive which addresses its incoming funds passed through, but there may be more than one, and some or all of them could belong to shared accounts. Actually, it's even possible to have no assignable "from" address at all - it's for example possible in the protocol to have a "spend to anyone" transaction, without defined recipient address.

Well, if you care about returning the money to the correct person, then you should worry to whom you send it! If you just want to get rid of the coins, feel free to send them to the address in my signature! :D

There's no guarantee that those in charge of a share wallet can determine that the refund you send was meant for person X. Actually, the address in question could be a deposit address of another person, or just a change address of the bank, anyway, it's impossible to know.

Do wallets not partition the funds into different bitcoin addresses?  Assuming they keep all of their deposits to hand this would seem like an easy way to manage things.  Even if they don't keep all the deposits, giving each account an expanding unique set of addresses for its external transactions seems wise given the low cost of bitcoin transfers. 


Can you explain further?  I suppose generated coins don't have any sender addresses (looking at the wiki they lack a scriptSig), but regardless of whether a transfer has a recipient for all its input coins it will surely have to have at least one when it makes it into a block (i.e. the block generator). 

No, they don't.

Bitcoin supports a flexible transaction scripting system that could allow you to redeem a transaction without using public/private keys for authentication (using a password, for example). Then there would be no "from" address, as the funds would not have been sent using an address, but with some other method.

Cheers.  Come to think of it it's unlikely the majority of them will hold a full reserve in the future, whatever they're doing now.



Okay.  I'm going to have to look further into this.  The transaction system is clearly even more complicated that I had thought. 

When you (and the wiki) say "redeem", do you mean "use in another transaction"?

Yes. When you redeem a transaction output, you take its coins and use it in another transaction's inputs.

Here's an example of a strange transaction without an automatically-detected address:
http://blockexplorer.com/testnet/tx/64f85bece3a019f452121440b553132e13f6a0daab2664463c122b5e0682047b
In this case, it would be possible to find a valid address from the unusual public key (and if lots of people made these transactions, BBE would do so), but this doesn't always have to be the case.

Well thanks for the input.

I am looking at starting a bitcoin related business.  In Australia bitcoins are classed as a non cash payment.  This means there are specific rules around how you handle customer payments.

Generally if you deal with less than $1000 worth per customer you can avoid any financial licensing issues. There are also issues related to your ability to refund unused coins etc. 

Taking on the suggestion that someone must provide a return address before they can deposit funds helps me stay within the local laws.

I can refund money if needed to avoid breach and I have a ready mechanism to return funds.

For those interested in the legal aspects of bitcoins related to Australia see here:
http://www.asic.gov.au/asic/pdflib.nsf/LookupByFileName/ps185.pdf/$file/ps185.pdf

That will be your best and most reliable method.

Any hints on what that business will be ?