Im getting an error when trying to broadcast a raw transaction with bitcoin core 22, min relay fee not met. My mempool has 5,000 + transactions and the fee rate is 2.0 s/b. I have not changed the settings in my bitcoin.conf, the node has 200+ days of uptime and plenty of 1s/b transactions sent without issue.

Any idea why I may be seeing this error?

Here is the request and response:

request: {"jsonrpc":"1.0","id":"B0FCBD68-507D-424A-8D64-0DAFB162FA4A","method":"testmempoolaccept","params":[["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"]]}
json: {
    error = "<null>";
    id = "B0FCBD68-507D-424A-8D64-0DAFB162FA4A";
    result =     (
            allowed = 0;
            "reject-reason" = "min relay fee not met";
            txid = 83338e540f4bdabed919eeb99d82db5979b5c62c89b70e7e3a856912db0ecc75;
            wtxid = 81521e8f742331ff1a5029aaa97a1bd10801244058f329ce58ea593a13042ee4;

1 Answer 1


The feerate is definitely not 2 sat/vb. It's less than 1 sat/vb, hence min relay fee not met.

Your transaction has a vsize of 141 vbytes. The single input has a value of 100000 sats and the single output is 99860. That's a fee of 140 sat, which results in a feerate of less than 1 sat/vb.

  • 1
    A common reason for the fee estimate being short a satoshi is that the signature is assumed to always be low-R, but the signer doesn't do low-r grinding.
    – Murch
    Aug 27, 2022 at 0:11
  • Thanks, I never would have figured that out. I am using bitcoin core for fee estimation but am doing my signing with Libwally, so this would potentially make sense.
    – Fontaine
    Oct 12, 2022 at 0:29

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