Electrum change addresses in Preferences

[Pmalek]

I just updated my Electrum software to the most recent 4.1.5 version.

After every install, I always check the preferences and settings to make sure that no unwanted changes were made or if some new features were added. I noticed that the "Use Change Addresses" option is unticked by default in 4.1.5. I can't remember from the older Electrum versions if this was ticked or unticked and why the developers would make changes if there were indeed made. My change has in the past always gone to change addresses.



When you can, please check your Electrum apps and let me know if this option is ticked or unticked in your settings. 
The way it is now, what happens with my change?
Should I tick this option?

My brain froze, I just can't remember how this looked like in the past...

[1714860500]

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[1714860500]

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[Charles-Tim]

I have just checked mine, it is ticked. Version 4.1.5, but I am surprised how 'advanced preview' is not ticked on my electrum wallet. Although, I downloaded it immediately it was released.

[Rath_]

When you can, please check your Electrum apps and let me know if this option is ticked or unticked in your settings.  

I installed Electrum 4.1.0 and 4.1.5 on Windows Sandbox and both of these version had this option enabled by default.

The way it is now, what happens with my change?  

The change will be sent back to one of your existing addresses rather than to a new address.

Should I tick this option?

Maybe? I always disable it and manually decide what to do with the change. You can use exclamation mark ("!") instead of a specific amount to spend the remaining value of the selected inputs. Example:

Input: 0.3 BTC

Code:

Address #1, 0.1
Address #2, !

"!" means that 0.2 BTC minus the transaction fee will be sent to Address #2.

[jackg]

It was selected automatically on mine - but I'm using the standalone version. It's a fresh install of everything because I was speeding up my computers - nothing copied across.

[Pmalek]

I just checked the Electrum preferences on my other computer where I have an older version of the software installed and the "use change addresses" option is ticked there. After a bit of thinking why it's different on 4.1.5, I can only think of the following two things:

• The option is unticked by default in version 4.1.5. DOUBTFUL
• I remember that the wallet I opened contains imported private keys. That must surely be the reason why the app unticked the option for any change to be sent to change addresses.

[jackg]

• I remember that the wallet I opened contains imported private keys. That must surely be the reason why the app unticked the option for any change to be sent to change addresses.

I think it's likely that one because I saw your option for using multiple change addresses was grayed out on your preferences menu while it's quite functional on mine.

[nc50lc]

When you can, please check your Electrum apps and let me know if this option is ticked or unticked in your settings.  

The 'change address' setting is saved in the wallet file itself.
You can see it as the line: "use_change": true, if the wallet file isn't encrypted.
The other settings however is saved in a file named "config" in the data directory.

So if you want to see the default for that particular setting, create a new sample unencrypted wallet and see what's in the setting.
Spoiler: it's enabled by default.

[NeuroticFish]

I remember that the wallet I opened contains imported private keys. That must surely be the reason why the app unticked the option for any change to be sent to change addresses.

While on a HD wallet change addresses help enhancing privacy, if you import the private keys it cannot do much (I don't know how it would even choose which to use as change address!)
So yeah, the fact it's disabled is 100% related to the imported private keys.

[hosseinimr93]

if you import the private keys it cannot do much (I don't know how it would even choose which to use as change address!)

In the version 4.1.3 and after that, if the "Use change address" option has been checked, electrum sends the change to one of unused imported addresses (if there's any, of course).
Prior to 4.1.3 update, the change was sent to the sending address even if the "Use change address" option had been checked.

[Pmalek]

...but I am surprised how 'advanced preview' is not ticked on my electrum wallet. Although, I downloaded it immediately it was released.

Advanced preview is unticked by default. I remember having to tick it manually back in an older version of Electrum when it was introduced.

Now I'm wondering what would happen with change if the box were left unticked. Would the change go to the source address?

If it's an imported private key (of only one address) like in my example, the software would have to send the change back to the same address the transaction was sent from. Anything else would be a serious bug. Since you only have the private key of one address, if the change were to go to another address, the coins would effectively be lost unless Electrum gives you an option to save the private keys of the new address.

What's interesting is that I have the option to tick the "use change addresses" option in my Electrum for the wallet with the imported private keys. Would Electrum give me an option to save the private keys of a change address in that case?

Prior to 4.1.3 update, the change was sent to the sending address even if the "Use change address" option had been checked.

Are you 100% sure about that? I had version 4.0.9 prior to updating to 4.1.5, and I believe (I can't be absolutely sure though) that change addresses were used in the past for my wallets.

[hosseinimr93]

Prior to 4.1.3 update, the change was sent to the sending address even if the "Use change address" option had been checked.

Are you 100% sure about that? I had version 4.0.9 prior to updating to 4.1.5, and I believe (I can't be absolutely sure though) that change addresses were used in the past for my wallets.

When it comes to HD wallets, you are right. In HD wallets, the change has been sent to a new address in all versions of electrum I have used so far.
In the above post, I was referring to the wallets created with importing private keys or addresses.

Read the 4.1.3 release note.

imported wallets: when enabling the "Use change addresses" option, change will now be sent to a random unused imported address. (#7330)
As before, by default, change is sent back to the "from address".