Confirmed transactions are irreversible. This is the nature of all blockchains.


BITCOIN

If a Bitcoin transaction is unconfirmed, there are a number of services that claim to accelerate confirmations, for example https://bitaccelerate.com and https://mempool.space/. Coinomi is not in any way affiliated with those services and cannot guarantee their efficacy. You can search for a trusted service that works best for you.


If you are the sender, you can check if the outgoing transaction on the blockchain explorer. If it has 2 recipients, it means that one of those is change returning to your wallet, and you can complete the steps below to make it confirm faster. This is a technique called "child pays for parent" (CPFP) 

  1. Copy your own Coinomi BTC receive address
  2. Paste the copied address in the send screen
  3. Use the "max" button to send all funds
  4. Proceed to the confirmation screen and select HIGH priority fee or a custom value even higher
  5. Send and wait for the transaction to confirm


If you use your BTC wallet a lot it may have many UTXOs, which when sent like this can add up to a large total fee. To save as much as possible, before starting the instructions above set all UTXOs as "do not spend" except the one received as change from the unconfirmed transaction. You can read about "do not spend" here.


Other options like "Replace By Fee" (RBF) exist but currently aren't available in Coinomi and cannot be used.


ETHEREUM

You can replace an unconfirmed Ethereum transaction that you sent from Coinomi with a higher fee, so that it confirms, or you can cancel it altogether, so that the funds never leave your wallet. 


Note: In Ethereum, transactions must confirm IN ORDER. That means that if you have many pending transactions, you must start by canceling or replacing the OLDEST one first.


To do so,

  1. Open https://etherscan.io and use the search bar at the top to search for your own Ethereum address.

  2. Scroll down and look at the list of transactions

  3. Find the "nonce" value of the transaction that you want to replace
    • If you can find the unconfirmed transaction on the list, open it, press the button "click to see more" to expand the details of the transaction and note its "nonce" value. The number 6 on the image below is just an example.
      Then proceed to step 4 below

    • If the unconfirmed transaction isn't listed on Etherscan, check the instructions here: https://coinomi.freshdesk.com/en/support/solutions/articles/29000037485

  4. Go to your Coinomi Ethereum wallet from which you sent the unconfirmed transaction.
    • TO REPLACE A TRANSACTION: Go to the "send" section and enter the same destination address and same value as the unconfirmed transaction that you are replacing.
    • TO CANCEL A TRANSACTION: Go to the "receive" section and copy your own address. Then go to the "send" section, and send 0 ETH (you have to type the number 0 in the amount field) to your own Coinomi Ethereum address that you copied before.

  5. Before you click "Next", click on the "advanced settings" and enter the nonce number that you found on step 4 at the "nonce" field. Touch NOTHING ELSE from the advanced settings. The number 6 on the image below is just an example.

  6. Continue to the confirmation screen. You will see 4 options: Select the "High" (Priority) fee option and send your transaction normally.

  7. After the new transaction confirms, at the top right corner of your ETH wallet select "... / Resynchronize" once to force a refresh of your transactions and clear the replaced ones.

  8. You're done. This new transaction will replace your pending transaction with the same nonce. On the block explorer canceled transactions have a status of "Dropped and Replaced" as in the image below



Note: every transaction that confirms on the blockchain must pay miner fees. The new transaction sent will pay the miner fees chosen on the confirmation screen. The old transaction that was replaced will not confirm, so you will not pay the miner fees for it.