Invalid private key problem.

[Leahhhh]

I've been helping a friend to sell some of her BTC. When we entered the private key in Electrum, it says it is invalid which we can hardly believe as when we created the wallets, we checked every digit of the private keys multiple times before writing them down. My question is if we have missed a digit or got one wrong, is there any way to recover the correct key (I don't think there is) or failing that we have the seed phrase that we made the wallets/keys from and I hope we can use that to make the recovery. Any advice would be appreciated. TIA.

[DireWolfM14]

The seed phrase is sufficient to recover the wallet.  In fact, that's exactly why seed phrases exist, so you don't have to write down individual private keys that are easy to bugger up...

[Leahhhh]

The seed phrase is sufficient to recover the wallet.  In fact, that's exactly why seed phrases exist, so you don't have to write down individual private keys that are easy to bugger up...

Thanks for your reply. Hopefully we will be able to recover it that way.

[mcdouglasx]

I've been helping a friend to sell some of her BTC. When we entered the private key in Electrum, it says it is invalid which we can hardly believe as when we created the wallets, we checked every digit of the private keys multiple times before writing them down. My question is if we have missed a digit or got one wrong, is there any way to recover the correct key (I don't think there is) or failing that we have the seed phrase that we made the wallets/keys from and I hope we can use that to make the recovery. Any advice would be appreciated. TIA.

If you have a seed phrase, it is not common to use private keys individually. It is impractical because with the seed phrase, you generate all the addresses you need. In fact, this is the primary function for which seed phrases were created, to facilitate the management of private keys and addresses. It is more convenient and secure.

I advise you to leave this habit before you make an irreparable mistake.

[nc50lc]

When we entered the private key in Electrum, it says it is invalid which we can hardly believe as when we created the wallets, we checked every digit of the private keys multiple times before writing them down.

Weird, Electrum will not say if the private key is invalid or valid, all it does is to prevent the user from proceeding if the private key isn't valid.
So, have you actually used (a legit version of) Electrum to sweep/import?

In Electrum:
If through "Import", in New wallet menu option "Import Bitcoin addresses or private keys".
If through "Sweep", it should be via "Wallet->Private key->Sweep" menu on an existing wallet that can spend from.

[Bitcoin Smith]

Hopefully we will be able to recover it that way.

It's pretty simple just go to Electrum

Standard wallet - I already have a seed - <Enter the 12 words seed>

Now your wallet with all the addresses along with balance will now appear in Electrum.

[Leahhhh]

When we entered the private key in Electrum, it says it is invalid which we can hardly believe as when we created the wallets, we checked every digit of the private keys multiple times before writing them down.

Weird, Electrum will not say if the private key is invalid or valid, all it does is to prevent the user from proceeding if the private key isn't valid.
So, have you actually used (a legit version of) Electrum to sweep/import?

In Electrum:
If through "Import", in New wallet menu option "Import Bitcoin addresses or private keys".
If through "Sweep", it should be via "Wallet->Private key->Sweep" menu on an existing wallet that can spend from.

Actually you are correct. I am mixing up what happened with a previous experience (could have been with Blockchain.com). Last night Electrum did not say anything - we just couldn't proceed.

[Saint-loup]

It's pretty simple just go to Electrum

Standard wallet - I already have a seed - <Enter the 12 words seed>

Now your wallet with all the addresses along with balance will now appear in Electrum.

If the seed hasn't been generated with Electrum, it won't be enough, he will need to use the BIP39 seed option instead. In addition he will have to check if the path is the same as the one of its funded addresses.
Besides that Leahhhh you haven't explained if you are trying to import them in a new wallet or if you are using the sweep feature with an existing one.

[dzungmobile]

I've been helping a friend to sell some of her BTC. When we entered the private key in Electrum, it says it is invalid which we can hardly believe as when we created the wallets, we checked every digit of the private keys multiple times before writing them down.

If your private key is invalid, how did you write it down again after checking every "digit" of it?

Because you and your friend tried to import private keys into Electrum wallet, let's read this guide.
Importing your Private keys into Electrum.
Click on Info (in the image).

You will a guide to import private key.
p2pkh:privatekey for address starts with 1
p2wpkh-p2sh:privatekey for address starts with 3
p2wpkh:privatekey for address starts with bc1

This is a guide for wallet backup as you and your friend will need to master it after having problems with wallet recovery this time.
How to back up a seed phrase?

[khaled0111]

Most wallets these days are hd wallets, which means you need the seed to recover it.
If you import a single private key then you will recover a single address and not the whole address.
So, as other members have explained, use the seed you have saved to recover your wallet. If you've created it with a different app then make sure to tick the bip39 checkbox when importing the seed into Electrum.

[BitMaxz]

Actually you are correct. I am mixing up what happened with a previous experience (could have been with Blockchain.com). Last night Electrum did not say anything - we just couldn't proceed.

Are you trying to import it to blockchain.com? That's a bad habit when importing a private or seed phrase you should always import them into of device.
Since you are trying to import it into Electrum I suggest use a device that never connected to the internet before importing your backup.

If you have missing or incorrect private key the button is greyedout.
Would you mind to tell us if how many characters in your friend's private key and what character is it in the beginning of the private key?

[LoyceV]

when we created the wallets, we checked every digit of the private keys multiple times before writing them down.

Which wallet did you use to create the private keys, and how many characters do you have written down?

My question is if we have missed a digit or got one wrong, is there any way to recover the correct key

If there's only a small mistake in writing, brute-forcing could still work.

[nc50lc]

-snip-

Actually you are correct. I am mixing up what happened with a previous experience (could have been with Blockchain.com). Last night Electrum did not say anything - we just couldn't proceed.

Can you trust this "friend" of yours that he's not just making up the story?

Anyways, since you've mentioned a seed phrase, Electrum has a neat auto-detect from common derivation paths feature, use it when restoring your seed phrase:
When you restore the seed phrase in "Standard->I already have a seed", open 'Options' and tick "BIP39 seed" then type your seed phrase.
In the next screen, Click the "Detect Existing Accounts" button and see if there'll be any result.
If there are/is, click it to create a wallet using it. Repeat the steps if there are more then one result but select the other result.

[Leahhhh]

Yes, I 100% trust this friend. She knows absolutely nothing about bitcoin; I set it up for her years ago and this is the first time that we have attempted to sell anything. I will get back to the person that asked what the first digit of the key is. I don't have them, she does and we will meet again later this week and try to solve the problem. Thanks in the meantime.