I made 3 btc transfer from my old Multibit classic wallet a few weeks ago (dec. 11), then I discovered that the fee was far too low for the transfers to be confirmed.

I then restored my original wallet into Electrum, and it shows me these 3 transactions with different status :

  1. Low Fee (44 sat/byte) - 0.0068 btc
  2. unconfirmed parent (52 sat/byte) - 0.04497458 btc
  3. unconfirmed parent (19 sat/byte) - 0.1221 btc

Unfortunately I cannot adjust fee on these transactions, so I tried a CPFP when making a new transfer from another wallet I created in electrum to my original wallet, but no result.

I tried to reproduce the 1st transfer, from the original wallet, same src/dest and amount but with Higher Fee (598 sat/byte)... no result.

I'm afraid to be stuck at this stage, I don't know what to do to unlock these transactions :( any detailed advice is welcome ! (i'm on OSX if asked).

  • Which transaction did you attempt a CPFP on? Do you have the transaction id for the 1st transaction and the RBF of the 1st transaction.
    – Chak
    Jan 2, 2018 at 16:42
  • transaction ID for the CPFP is e9723fdf6c923a278304e7bffcd3089f4175dabf2ca1702516718195e005e5dd
    – soleshoe
    Jan 2, 2018 at 17:13
  • the transaction ID of the 1st transfer is : 364e89a750dea40d8bfe1939b431abe6e90abdd3c80230c7c8dd199172061cbf
    – soleshoe
    Jan 2, 2018 at 17:14
  • no RBF with multibit
    – soleshoe
    Jan 2, 2018 at 19:03
  • I wouldn't say it is a duplicate, since the user already attempted to CPFP and RBF, but he did it incorrectly. The answer therefore helps him solve his mistakes.
    – Chak
    Jan 3, 2018 at 18:16

1 Answer 1


Seems like your 589 Sat/Byte went through now, however that transaction is not a double-spend of your 1st transaction because the total output Total Input amount is different.

Transaction e9723fdf6c923a278304e7bffcd3089f4175dabf2ca1702516718195e005e5dd is also not a CPFP of the 3 transactions you mentioned above.

If you want to attempt a CPFP on those 3 transactions, you have to spend the unspent output 17HiELrskFprzREjeLDYNuDARV64Q59Ta6, transaction cf617f5908f89c604a5a575b0eac1c570141868569be38510da8916d5f397628.

Did the math for you:

Add all transactions including your new soon to create CPFP transaction:
Great-grandparent + Grandparent + Parent + Child
225 Bytes + 521 Bytes + 192 Bytes + 192 Bytes = 1130 Bytes

Then add up all paid fees:
10000 Sat + 10000 sat + 10000 sat = 30000 sat

Divide to get current Sat/Byte:
30000 Sat / 1130 Bytes = 26,55 Sat/B

Estimated fee to confirm within 60 min. At least 379 Sat/Byte. 
Check out https://estimatefee.com
Subtract to find difference needed:
379 - 26,55 = 352,45 missing Sat/B

Fee for new CPFP transaction:
352,45 Sat/B * 1130 Bytes = 398268,5 sat = 0.00398268 BTC

Fee per byte for the new CPFP transaction:
398268,5 Sat / 192 Bytes = 2074,3 Sat/B

Make a new transaction, send BTC from 17HiELrskFprzREjeLDYNuDARV64Q59Ta6 with a minimum fee of 2074,3 Sat/B and all your transactions will most likely confirm within 60 min. Or ask miners for help.

Click here for visualization of double spend

Click here for double spend example with Electrum.

How to double-spend(if your client allows it):

For example directly to your Bittrex address and some changes to yourself:
Create a transaction that spend the same 
Unspent Transaction Output(0.16123728 BTC) as in your 1st transaction.

FROM 1GeAmqqQn1LxBebtt6tmuPVHfzEo9jWPrH (0.16123728 BTC)
TO   17HiELrskFprzREjeLDYNuDARV64Q59Ta6 (0.04497458 BTC)
AND TO  1GeAmqqQn1LxBebtt6tmuPVHfzEo9jWPrH (0.1153587 BTC)
With 400 Sat/B as fee.
If I did the math correctly this transaction should have total output 0.16033328 BTC.

Or if you prefer to send it all to yourself: 
FROM 1GeAmqqQn1LxBebtt6tmuPVHfzEo9jWPrH (0.16123728 BTC)
TO   1GeAmqqQn1LxBebtt6tmuPVHfzEo9jWPrH (0.16123728 BTC - fee)
Include a reasonable fee(estimatefee.com) so it confirms within your desired timeframe.
If this transaction gets confirmed first, then your 3 transactions mentioned above will be rendered invalid/disappear.

  • Problem is that 17HiELrskFprzREjeLDYNuDARV64Q59Ta6 is my bittrex btc address, so I can make a new transfer, but no CPFP i guess... will it work ?
    – soleshoe
    Jan 3, 2018 at 15:39
  • You can't CPFP, because Bittrex won't allow you to spend unconfirmed output and also they have a fixed withdrawal fee. I have 2 suggestions for you. 1. Some members on bitcointalk.org offer free TX acceleration services ,you can post on their thread and ask them to accelerate your transactions for you.(Or go for the paid services, but beware of the scammy ones). OR 2. Attempt to double-spend your 1st transaction if your client allows it, this time using the right input amount of 0.16123728 BTC
    – Chak
    Jan 3, 2018 at 18:01
  • Sorry, I don't understand the second option :/ How to double spend 1st transaction (0.0068) can give a total of 0.16123728 ? I'm lost
    – soleshoe
    Jan 3, 2018 at 20:41
  • Added steps for you. See answer.
    – Chak
    Jan 3, 2018 at 22:56
  • Oh my ! :/ I tried the second solution first, and just realized that the amount to send to myself is my actual wallet balance if i'm right ? The idea is to spend all wallet content to myself I guess ? I'll have to restart then... so many fees lost :(
    – soleshoe
    Jan 4, 2018 at 12:22

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