[NOTICE] If your second payment includes the amount from an unconfirmed payment

[NotATether]

Sometimes, after you make a payment to some address in Electrum, when you make a second payment, you will notice that it includes the addresses and amount to pay from one or more previous unconfirmed transactions. It happened to me while I was creating a payment while my first payment was unconfirmed.

In particular, if you pay X BTC to address Y in the first payment, and you want to pay XX BTC to address YY in a second one, the transaction will send a total of X+XX BTC between Y and YY.

This happens if your transactions are using RBF, so you need to go to Tools > Preferences > Transactions and uncheck "Batch RBF Transactions".

I hope this helps other people who also run into this problem.

[Abdussamad]

batching saves fees and reduces the amount of space taken up on the blockchain. so it's a good thing overall. you should not disable that option.

[o_e_l_e_o]

so it's a good thing overall. you should not disable that option.

It's good for fees, but it is bad for privacy. It undeniably links the inputs to both transactions as both belonging the same wallet. This may be inconsequential, but this also may reveal a lot about one of the transactions which you did not want it to, such as allowing an exchange to track and deanonymize other transactions you have made.

[NotATether]

so it's a good thing overall. you should not disable that option.

It's good for fees, but it is bad for privacy. It undeniably links the inputs to both transactions as both belonging the same wallet. This may be inconsequential, but this also may reveal a lot about one of the transactions which you did not want it to, such as allowing an exchange to track and deanonymize other transactions you have made.

We can't be certain that exchanges are not tracking us although they should not be, if I held a bank account I wouldn't think that it's not reading my transactions and using them for its own commercial purposes either.

Just unbatching fees alone is not going to stop people from correlating your future transactions. You have to throw in a lot of unrelated inputs and outputs as well to throw them off somewhat.

Since it's an exchange we're talking about, making throwaway addresses won't help, if it's even possible to make new addresses, since the exchange has your private keys and knows the derivation paths it used to make your addresses.

[o_e_l_e_o]

Since it's an exchange we're talking about, making throwaway addresses won't help, if it's even possible to make new addresses, since the exchange has your private keys and knows the derivation paths it used to make your addresses.

I was meaning if the transaction out of your wallet were to or from an exchange. For example:

Let's say I have withdrawn coins from a large centralized exchange I have completed KYC on to address A. A friend of mine has also sent me some coins to address B. These two transactions and addresses are completely unlinked. Now, with the bitcoin price climbing, I decide to sell some bitcoin. I send the coins from address A back to the same exchange. I also decide to send the coins from address B to a casino to make a few bets. Electrum batches these transactions together. There is a high likelihood that the exchange will link my transaction to the casino, and if they are an exchange which does not allow this kind of behavior, potentially freeze my deposit and lock my account.