Topic: Any means of combining multiple output into 1 ? (Read 335 times)

Good to hear that you have actually got your problem solved,

It seems you are mixing up some terms here, although it is technically possible to generate two different wallet with one private key or seed phrase but in this your own case it is not 30 or 20 different wallet as you have put them out but rather those where addresses. With an HD wallet you can have master private key which generates extended or child private keys and then public key which in turn generates addresses. So what you actually have is a master private key and those were addresses and not different wallets. This master private key can also generate more than that 20 addresses or even more than 30 addresses as you thought it couldn’t. The reasoning you’re seeing 20 of them is because of your wallets gap limit which is set at that number.

The way it works is that once a new address receives bitcoin then a new wallet is created. For example of there is 20 free addresses there (those that haven’t received any bitcoin before) then one of them receives bitcoin, another address will be created to make them 20 free addresses again. So on those addresses the reason why you saw particular address that received more than one transaction appearing like it’s a separate thing is because bitcoin treats each received transaction as an UTXO and even if one address received 10 separate transactions it will be 10 UTXOs on that same address and when sending everything from them they will appear as 10 inputs and not one input.

@Zaguru12, @Charles-Tim, @DannyHamilton, @hd49728, @Yamane_Keto, @LoyceV, @dkbit98, @satscraper, @BitMaxz, and @BlackHatCoiner,

Sorry, it took me this long to reply. I was not clear enough on the Op; I only assume there are 30 wallets, which I don't think they are up to, but they are above 20 wallets, and these wallets are controlled by one private key. Electrum gives me a lot of wallets to be used, and new ones can also be generated if I want.
 
So the transaction is spread across all these wallets. Some receive two-time transactions from different senders, while others receive only a single transaction. If I send them to a single wallet, the size might be too large and more expensive, which was the reason for my question.
 
A few days ago, I was able to empty the wallets, which I did not do all at once. I sent them out bit by bit until I finally sent them all out yesterday.

Creating a transaction which spend all UTXO and send it to an address almost always best way to reduce TX size and fees. OP doesn't mention he has UTXO with very small amount of Bitcoin which could make my previous sentence incorrect. And there's no thing such as wallet with fee optimization. What you can find is wallet which suggest fee rate and let you set custom fee rate.

When receiving many small deposits in different wallets, sending them all at once to a new wallet may not significantly reduce fees. Use a wallet with fee optimization for better cost efficiency when combining multiple inputs into one output.

sat/vB is important.
Dollar value for sats would get lower, but in most cases this big dumps would probably create a lot more transactions that would increase fees again.
Lowest fees for bitcoin are usually in times of low blockchain activity during bear markets with bunch of bad news.
This are ideal times for consolidation.

OP, note that with current fee rates, you'll have to pay quite a lot. Spending 30 inputs takes up about 2000 vbytes. With fee rate at 45 sat/vb, that will cost 90,000 sat at least.

Technically speaking, the transaction fee is not considered an output. From the perspective of the protocol, the sum of all the outputs minus the sum of all the inputs is the transaction fee.

If you mean that these 30 wallets are BTC addresses from a single wallet if you are using Electrum if you created a new transaction or sent it to one of your wallet addresses they would combine and become a single UTXO.

Why not try to tell us what wallet you currently use? If it's not Electrum you will need to export all private keys of these 30 wallets and import them to an offline device as suggested by LoyceV and get the 30 public keys or BTC addresses and import them to online Electrum and make an unsigned transaction it should automatically includes all UTXO  then export it and import the raw transaction into offline Electrum and sign it copy the signed rawTX and import it to online Electrum then rebroadcast.

Just make sure that you send it to a single BTC address if you want to merge all UTXO.

The only way to combine 30 UTXOs is to use them as inputs for a new transaction with two outputs (one of them would define a fee for miners while other - send the rest to new address).

At the current fee rate the no-nonsense approach would be leave them in the raw and spend one by one as the need required, IMHO.

Both panic buy and panic sell could happen, so it's not strong guarantee we'll get lower fee (either in terms of fiat or sat/vB). In addition, attack by creating many transaction (when it's not needed) might happen regardless of Bitcoin price changes.

The fee we set for our transaction is decided by the traffic on the mempool at the time which can be as low as possible which is 1sat/vb or crazy high as of now due to congestion which is irrespective of the value of bitcoin.

Practically, there will be a lot of activity going on the network when there is a surge or correction which increases the traffic but it what we face is beyond that, and its due to the invasion of the network by spam transactions in the name of brc20 project.

If the price of Bitcoin dumps, shouldn't we get lower fees ?
Even if it goes up for a few more months or even years who knows, there's a point where we will get small tx fees.

Like it or not, fees are going to get even higher in next few years, so think about using some alternative option if you are constantly receiving smaller amount of bitcoin on many addresses.
Best way I found so far is to use L-BTC liquid network addresses, they will get consolidated for free using Aqua wallet, and when you collect enough coins and fees are not extremely high than you can swap them to on-chain Bitcoin.
Compatible wallets so far are Aqua wallet, Blockstream Green wallet, Jade hardware wallet, ledger wallet, specter wallet.

Are those 30 wallets yours, or do the funds come from other people? If the wallets are yours, you could import all keys into one (offline) wallet instead of sending them, and then create one large transaction to create one new input.

Also note that consolidating 30 different wallets is bad for privacy.

Using coincontrol you can reduce the number of inputs and enhance privacy, but you need to make sure that the output is smaller than the sum of the inputs and thus save more fees or start using Taproot address as Input vbyte is only 57.5 and the size of a simple transaction is 154 vbytes (1 input 2 output.)
154*50 sat/vB*0.00000001*42,662=$3.2 fees only

First, you must be clear here.

Do you have 30 different addresses, UTXOs in a same wallet or Do you have 30 different addresses in 30 different wallets?

If it is a first situation, 30 different addresses in a same wallet, it will be easier to consolidate your 30 UTXOs (inputs) into one output. You only have to wait for Bitcoin mempools to be cleaned and give you cheap transaction fee rates to consolidate your inputs.

Guide to consolidate small inputs.

If it is a second situation, it will be more complicated and you will have to import 30 private keys into one wallet and sign your consolidation transaction from that wallet.

Note that the Output, the receiving address after your consolidation, should be a Segwit address. Because it will help you to save transaction fee in future when you need to move your coins.

Why people should be using SegWit addresses

Here is some useful information about fees in general, but it sounds like you may already be aware of much of this:
https://en.bitcoin.it/wiki/Techniques_to_reduce_transaction_fees

The only way to "combine" outputs is to use them individually as inputs in a transaction, and then have that transaction create a single output (or just a few outputs?).

However, here are a few things you might consider.

• Use coin control, and make sure to select your highest value outputs when building transactions during times of higher than average fees. This will reduce the number of inputs you need to use.
• If you have a set of outputs that you're confident you won't need for quite a while, create a transaction using them now . Set a low fee on that transaction. Then just wait. Eventually, when the fee requirements dip a bit, your transaction will get confirmed, and you'll awaken to a nice consolidated output.
• Keep an eye on transaction fees, and when you see them dipping low enough, combine outputs so you'll be ready for the next time the fees go up.

Patient is my name, I must say, and thanks for the straight-up answer, as it shows that there is no way rather than just waiting for the fee to go back to normal.

There is absolutely no way it can be combined and be treated as one input because a bitcoin transaction treats each UTXO as a single input transaction. Just keep calm and consolidate your inputs later now is not the right time.


OP wants to have them as one input before sending them out which is not possible

You can convert 30 inputs into 1 input by sending all the UTXOs to the same address or any of the address you own, and that is the only way to combine inputs and simply it's called consolidation which you should normally do when fee is low, like 1 sat/vb to avoid paying huge fee when network is highly congested like right now.

Be patient and hope that mempool high fee priority can get as low as 1 to 2 sat/vbyte again.