Help with Coin control, importing private key from Trezor to Electrum

[Icygreen]

I would like to learn how to utilize coin control (spend specific UTXO's) which are currently on a Trezor.  The object of this is to consolidate many inputs of a specific address on that wallet without.   Trezor does not provide coin control, I understand the trezor private key will need to be imported to a different wallet which supports this.  I'm unsure how to do this, the risks, and the steps to controlling the specific UTXO's.

 Running latest Trezor fw and Electrum 3.3.8
Thank you!

[Rath_]

Trezor does not provide coin control, I understand the trezor private key will need to be imported to a different wallet which supports this.  I'm unsure how to do this, the risks, and the steps to controlling the specific UTXO's.

You don't have to expose your private keys in order to be able to use coin control in Electrum. Open Electrum, create a new standard wallet and select 'Use a hardware device'. Once your device is detected, you will be prompted to select the type of address you used - legacy (1...), nested SegWit (3...) or native SegWit (bc1...). You might need to modify the derivation path during this step. Which type of address did you use? Are you trying to access the address from the first account or some other one? Your derivation path should look like this:

Legacy: m/44'/0'/account'
Nested SegWit: m/49'/0'/account'
Native SegWit: m/84'/0'/account'

'account' is the number of the account you are trying to access. The first account is 0, the second is 1 and so on.

[jackg]

As bitcryptex says but you also need trezor Bridge installed (you said you have trezor firmware so I'm just making sure that includes the bridge)...

If you're wanting to spend from a specific address/addresses you can right click on the addresses tab and select "spend from". You could also use preview to check you're doing it all the way you wanted to (alternatively there's a way to add all inputs to that window and deselect the ones you don't want afaicr).

[DireWolfM14]

Once you have your wallet connected to Electrum, click on View and enable the "Coins" tab.  All of your UTXOs will be listed there.  You can manually select the ones you want to consolidate, then right-click, and select "Spend from."

[Icygreen]

Oh wow, didn't realize this is easier than expected. Will give it a go and report later. Thanks for the super help guys!
It's a nested segwit 3 address.   
I'd like to batch all inputs of that address and send the consolidated tx to the same address. 

[Abdussamad]

>I'd like to batch all inputs of that address and send the consolidated tx to the same address. 

why? seems like a waste of money to do that

[o_e_l_e_o]

Oh wow, didn't realize this is easier than expected. Will give it a go and report later. Thanks for the super help guys!

There's also a guide on Trezor's Wiki if you get stuck or you want pictures to guide you through the process: https://wiki.trezor.io/Apps:Electrum
For a nested segwit account, you'll want to pick "p2sh-segwit (p2wpkh-p2sh)" on the fourth screen.

seems like a waste of money to do that

Why is it? If he has lots of inputs at that address, then consolidating them together when the fees are currently low (currently 4-5 sat/vbyte will get you confirmed within the next few blocks) could save a lot of money if he needs to make a transaction later when the fees are higher. Given fees were up at over 100 sat/vbyte just a few days ago, consolidating inputs when the fees are low is always a good idea.

[jackg]

>I'd like to batch all inputs of that address and send the consolidated tx to the same address. 

why? seems like a waste of money to do that

Yeah like loyce says, do it around 1 sat per byte (I do anyway) and shift everything to one utxo for when fees become high again...

If you can save something for someone else on fees then you may as well even if it doesn't look like much...

[HCP]

I sent a transaction on Thursday night in the middle of big network stampede when the price broke $9K... using a fee of 1 sat/byte... 168 sats total fee and it "only" took 4 days to get a confirmation

You can consolidate your coins whenever you like... doesn't just need to be when fees are low... just don't expect it to be fast!

[Icygreen]

Easy peasy with everyone's help, was concerned it was going to be a much longer process to understand and remember.

[Icygreen]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating? 

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?
What are optimal input/output values for an address as it would relate to fees in the future when it's spent? 

[Rath_]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating?  

It looks like you are a bit confused. There is nothing to consolidate here. Your address was one of the 142 outputs in that transaction. The number of its inputs is irrelevant. Since that output has been included in a transaction, it is now an Unspent Transaction Output (UTXO).

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?

That UTXO can now be used as an input in a new transaction. Since you received only one transaction to your address, you will only have one input. If there is any change left from an input then another output is created. That output points to one of the addresses from the same wallet (either a change address or the address from which the coins were sent). If you received 10 transactions and wanted to spend all of your coins then you would have 10 inputs.

What are optimal input/output values for an address as it would relate to fees in the future when it's spent?

The more inputs and outputs you have in a transaction, the more fees you have to pay. Note that if you had to send the same amount of coins in separate transactions, you would pay more. As for the optimal values, let me quote LoyceV.

Example
18 days ago, someone made this 4909 bytes transaction with 33 inputs and 510 Satoshis/byte fee. After paying fees, his 0.033BTC turned into only 0.0079539BTC. If he would make the same transaction now with 20 Satoshis/byte fee, he would have saved 0.024BTC. Instead of just 0.0079539BTC, he would have ended up with 4 times more!

[Icygreen]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating?  

It looks like you are a bit confused. There is nothing to consolidate here. Your address was one of the 142 outputs in that transaction. The number of its inputs is irrelevant. Since that output has been included in a transaction, it is now an Unspent Transaction Output (UTXO).

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?

That UTXO can now be used as an input in a new transaction. Since you received only one transaction to your address, you will only have one input. Outputs are the addresses which will receive the coins from you. If there is any change left from an input then another output is created. That output points to one of the addresses from the same wallet (either a change address or the address from which the coins were sent). If you received 10 transactions and wanted to spend all of your coins then you would have 10 inputs.

Yes, confused looking at explorer.bitcoin.com. I see, the outputs and fees are referencing the block not the address. Thanks for clarifying this, So a normal transaction to a single address where the entire balance is not spent will create 2 inputs and 2 outputs on the network and 2 new UTXOs.  One input and output to both the receiver and the change address of my wallet.

[Rath_]

One input and output to both the receiver and the change address of my wallet.

Not really but you are close. The number of inputs is related to the amount of coins you want to spend; not to the number of recipients. If you had two UTXOs - 0.1 BTC each and wanted to sent 0.15 BTC, you would use up 2 inputs and have 2 outputs. However, If you sent 0.05 BTC, you would use up 1 input and still have 2 outputs because of 0.05 BTC (minus the transaction fee) change .

[Abdussamad]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating?  

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?
What are optimal input/output values for an address as it would relate to fees in the future when it's spent?  

See this is why i said it's pointless. OP does not understand and that's the case with 99% of users who ask about consolidating coins or whatever.

@OP You've been reusing addresses and that's why over time you've received many coins and spent many of them as outputs. Now you have just one unspent output (utxo) and that's why when you choose to spend from that address it creates a transaction with just one input which is the sole utxo remaining.

I suggest that you not reuse addresses in future but there is no need to move your bitcoins around.

[Icygreen]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating?  

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?
What are optimal input/output values for an address as it would relate to fees in the future when it's spent?  

See this is why i said it's pointless. OP does not understand and that's the case with 99% of users who ask about consolidating coins or whatever.

@OP You've been reusing addresses and that's why over time you've received many coins and spent many of them as outputs. Now you have just one unspent output (utxo) and that's why when you choose to spend from that address it creates a transaction with just one input which is the sole utxo remaining.

I suggest that you not reuse addresses in future but there is no need to move your bitcoins around.

The point of creating this thread was to get help and guidance to further educate myself. I fail to see what you find pointless. Perhaps you have not read the thread?
Next, you're incorrect. I have never spent from this wallet but I have generated multiple inputs (from a single source) for certain addresses. Because I've never spent, I've never reused any address where security or privacy are traded off.

[Abdussamad]

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating?  

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?
What are optimal input/output values for an address as it would relate to fees in the future when it's spent?  

See this is why i said it's pointless. OP does not understand and that's the case with 99% of users who ask about consolidating coins or whatever.

@OP You've been reusing addresses and that's why over time you've received many coins and spent many of them as outputs. Now you have just one unspent output (utxo) and that's why when you choose to spend from that address it creates a transaction with just one input which is the sole utxo remaining.

I suggest that you not reuse addresses in future but there is no need to move your bitcoins around.

The point of creating this thread was to get help and guidance to further educate myself. I fail to see what you find pointless. Perhaps you have not read the thread?

lol i wasn't saying the thread is pointless. i'm saying consolidating inputs is pointless like i said above in my first post in this thread.

Next, you're incorrect. I have never spent from this wallet but I have generated multiple inputs (from a single source) for certain addresses. Because I've never spent, I've never reused any address where security or privacy are traded off.

If a) you've never spent  and b) you've received multiple transactions to the same address then doing a max send from that address in electrum should not lead to a transaction with just one input. So not sure what's going on here. A spend from a specific address is where you go to the addresses tab (view menu > show addresses if you can't see it),  right click on the address in question and choose spend from. Is that what you're doing?

[Rath_]

lol i wasn't saying the thread is pointless. i'm saying consolidating inputs is pointless like i said above in my first post in this thread.

So, you don't mind paying more for a ~90 sat/byte transaction with multiple inputs when the fees spike instead of consolidating them at 1 sat/byte and making a small ~90/byte transaction? Here is an example. Let's say you have 20 inputs and need to send all of your coins to a single address (assume all addresses are legacy).

Without consolidation (90 sat/byte): 0.0027036 BTC
With consolidation: 0.00003004‬ BTC (at 1 sat/byte) + 0.0001728‬ BTC (at 90 sat/byte) = 0.00020284 BTC

The savings are quite clear to me.

If a) you've never spent  and b) you've received multiple transactions to the same address then doing a max send from that address in electrum should not lead to a transaction with just one input. So not sure what's going on here.

I've got an address with a single transaction with 11 inputs and 142 outputs.

I have never spent from this wallet but I have generated multiple inputs (from a single source) for certain addresses.

Apparently, OP sent a large transaction with 11 inputs and 142 outputs. One of those outputs, was his address from Electrum.

[Abdussamad]

Apparently, OP sent a large transaction with 11 inputs and 142 outputs. One of those outputs, was his address from Electrum.

Man read the rest of that post:

I've got an address with a single transaction with 11 inputs and 142 outputs. Is this something worth consolidating? 

In electrum preview spending from that address with max selected, it shows 1 input 1 output. Will this be the new input/output values of the address if I send max?
What are optimal input/output values for an address as it would relate to fees in the future when it's spent? 

Spending max from that address is showing just one input. He's been reusing addresses or he's otherwise confused.

Anyway the whole thing is likely a wild goose chase.

[HCP]

Spending max from that address is showing just one input. He's been reusing addresses or he's otherwise confused.

I agree that the OP is confused.

It would appear that the OP had an address that received payment from a transaction that had 11 inputs and 142 outputs. ie. they received a payout from a service provider like an exchange/gambling site etc that used "Pay2Many".

They're checking the transaction details on a blockexplorer and seeing "142 outputs"... not realising that only one of those 142 UTXOs is actually related to their wallet. Thus, when they go to "max" it only shows the 1 UTXO being used as an input, as that is all that is actually controlled by their wallet.