Increase in Bitcoin transaction fee when the network is busy

[SeriouslyGiveaway]

The guides you shared don't fully reflect the changes made to more recent versions of Electrum.
Since desktop version 4.6.2 and mobile version 4.7.0, all you need for making a transaction with a fee rate of less than 1 sat/vbyte is to be connected to a server that accepts such transactions.

In older mobile versions, it was not possible to make a sub 1 sat/vbyte transaction at all, and in older desktop versions, you needed to use a command in the console.

Thank you for detailed explanation.

By the way, I'd like to ask you one question about Replace By Fee. Sometimes, I can bump the fee rate of my pending transactions. Some other times, I can not bump the fee. I don't remember the exact message from Electrum but it's like the server does not allow me to bump fee, something like this.

Is it like Bitcoin nodes can customize their node settings and allow Bitcoin users to bump fee rate or don't allow it?

[Cookdata]

Thank you for detailed explanation.

By the way, I'd like to ask you one question about Replace By Fee. Sometimes, I can bump the fee rate of my pending transactions. Some other times, I can not bump the fee. I don't remember the exact message from Electrum but it's like the server does not allow me to bump fee, something like this.

Is it like Bitcoin nodes can customize their node settings and allow Bitcoin users to bump fee rate or don't allow it?

Electrum RBF is enabled by default, the server shouldn't reject it. If the server you are connected to is not accepting the new transaction, go to your network settings and manually select another server from the list, then right-click and "use as a server". Once your wallet is synced, then replace the transaction you want to be replaced.

Make sure the replaced transaction fee is a slightly higher than the previous fee too.

[alastantiger]

Someone made mention in the comment that the fees are not as high as you said your friend did. First it's true that when there is high congestion of traffic, the fees get high and those that pay it make their transactions go faster. Since the fees like a commentator said is relatively low, what if the used an exchange that added additional fees to the transaction that made it look like the fees are high.

Exchanges are known to over pay for their transactions because they do not want their transaction to be delayed when you withdraw but if they pay that high fees, it does not mean that the network is now congested and all fees are high. If still fees are high and you are using a non custodial wallet that allows you to adjust your fees then you can pay the moderate fee and wait for your transaction to confirm which will happen in few minutes. It has been very long last when the market became congested that it took hours before a confirmation was gotten. I have been very active with Bitcoin almost all the time recently and there has not been any time the fees was too high for me to experience any delay in my transactions hence I do not also understand why the OP was thinking that the fees are too high.

[hosemary]

By the way, I'd like to ask you one question about Replace By Fee. Sometimes, I can bump the fee rate of my pending transactions. Some other times, I can not bump the fee. I don't remember the exact message from Electrum but it's like the server does not allow me to bump fee, something like this.

Is it like Bitcoin nodes can customize their node settings and allow Bitcoin users to bump fee rate or don't allow it?

Nodes can have their own settings, but they all should allow RBF-enabled transactions to be replaced with new ones.
If the server didn't accept your replacement transaction, chances are your transaction didn't follow BIP125 rules. Maybe the fee you used for the replacement transaction wasn't enough. This is just a guess and could be wrong.

[nc50lc]

Maybe the fee you used for the replacement transaction wasn't enough. This is just a guess and could be wrong.

That's a good guess actually.

Since he mentioned "sometimes" and Electrum always flag its transactions as replaceable, so no need for full-rbf enabled servers.
It must be Electrum's rbf fee calculation issue (that is limited by its SPV design):
Electrum just fails to calculate the correct additional fee in instances where the transaction has more than one descendants, it can only count the fees of the to-be-evicted transactions that it knows.
So during broadcast to server, it'll fail to satisfy condition 3 even though the user used its suggested new fee rate.

[Coindrill]

One point that helps beginners is that the fee is an auction for block space, not a percentage of the amount you send, so a small payment can cost the same as a large one if the transaction is the same size. What matters is the fee rate in sat/vB and how many inputs your wallet has to use, which is why consolidating lots of small UTXOs when fees are cheap saves you money later when the network is busy. If a payment is not urgent, the cheapest fix is often simply to wait for quieter hours instead of accepting the wallet's high priority estimate straight away. Using SegWit addresses also keeps each transaction smaller and therefore cheaper than older address formats. And keep in mind an exchange withdrawal fee is a flat charge set by the exchange, which is different from the actual on-chain fee miners receive.

[CryptoNewbie2026]

This explains a lot. I paid way more than expected on my first on-chain transfer because I didn't realize I was basically bidding for block space. Is there a rule of thumb for what fee to set when the network isn't congested vs when it is?

[Cricktor]

Is there a rule of thumb for what fee to set when the network isn't congested vs when it is?

What do you define as a not congested network aka mempool? It's highly unlikely that there aren't enough transactions to fill a few blocks with a minimum relay feerate of 0.1sat/vB, especially with all this Runestone crap and whatnotelse.

So, I predict that mempools won't dry out of transactions for a long time. There will likely be at least enough transactions in mempool somewhere in the ballpark of 25-45 blocks worth of space for quite some time (weeks, months). Most of them will be in the very cheapo camp of 0.10-0.21sat/vB and will take a long time to be confirmed.

If you want orientation have a look at the transaction fees prediction of mempool.space which is usually quite good, see screenshots of current state below.



For context, these are the candidate block and a few of the last mined blocks.



Highlighted are the minimum feerates that made it into blocks. I would have a look at those and maybe take the average of past few minimums, omitting extreme values, and add maybe 10-20% if your goal is a confirmation target of next one or two, maybe three at worst blocks.

If your transaction isn't urgend, go for the low priority value of mempool.space. The "no priority" value might take very long to be confirmed, days or even weeks. Currently a feerate of 0.2sat/vB isn't likely to be confirmed in weeks and many nodes have a default setting of dropping a transaction after 14 days of not being confirmed in a block unless it is rebroadcasted.