Improving the Coin control feature

I made two Bitcoin transactions in Trezor Suite with RBF enabled.

1’st transaction:
BTC sent from two Inputs to one Output with option “Send max” enabled where Inputs are from one wallet, and the Output is from another wallet (another seed-phrase). After some time, I wanted to increase the fee to speed up the transaction, but there were no free funds at the input addresses, but Suite offered to increase the fee nevertheless, and I used it. As a result, the fee was taken from another last address which received btc of the same wallet.

In this case, could Trezor offer me to choose an address from which funds would be taken to increase the fee? The Trezor Suite just offers to do this, but does not show which address the funds for the fee will be taken from, and even more so does not allow you to choose any other address for this.

2’nd transaction:
BTC sent from four Inputs to one Output with option “Send max” enabled where Inputs and Output is a same wallet (same seed-phrase). After some time, I wanted to increase the fee to speed up the transaction, but in this case Trezor Suite don’t allow me to increase the fee, the Replace transaction button was disabled (grayed). I have enough btc on different addresses of this wallet but I can’t bump fee with using btc from another address as in 1’st transaction. Perhaps, to get out of this situation, I should transfer a little bit of btc to one of the Input addresses of the incomplete transaction to enable state of RBF. I tried to send some quantity of btc to one of Inputs (second address) and still can’t bump the fee :pensive:

So, my suggestions for improvement:
Allow to select an existing address of the same wallet for using btc to increase the fee if the “Send max” option was used or if there are not enough funds for the required fee at the address. Display more information about which address will be used to increase the fee. As I see it, RBF works differently if the transaction is external and internal.

I’m sorry if I explained everything in a muddle.

[Solved]

The problem:
I sent all btc with low fee 2 sat/B from address #1 to address #2 with RBF and “Send max”. I don’t have additional satoshi to increase the fee by RBF, it was inactive. I added funds to the address #1, but it did not help to make RBF active. The transaction was stuck for several months. :pensive:

The solution:
In Trezor Suite I make the new RBF transaction from address #2 (with unconfirmed transaction) to address #3 to which I have access and control and set a “double”+ fee which will be more than enough for two transactions. (Now RBF could be changed). The transaction has become marked as CPFP (Child Pays for Parent) and both transactions were confirmed quickly. :blush:

I discovered CPFP by accident and this was my first experience. There is no mention of this in the Trezor Suite application, only some mention in the help documents. It would be useful to add detailed information about this to the Suite along with RBF information.

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Hi @Viktor_1BTC,

CPFP is an advanced method of fee bumping. We usually suggest this method in tickets only if there is no other option how to unblock funds in unconfirmed transactions.

Great to read that you managed to perform CPFP!

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