we faced the utxo failure issue

the error message is like message: '"transaction submit error ShelleyTxValidationError ShelleyBasedEraAlonzo (ApplyTxError [UtxowFailure (WrappedShelleyEraFailure (UtxoFailure (FeeTooSmallUTxO (Coin 272465) (Coin 269165))))])"',

What is the problem? We tested many times successfully but the error only occurred when it went to mainnet

Here is our policy id if anyone could help look into the transaction and find out what the problem is? https://cardanoscan.io/tokenPolicy/2fd5b51792a29d9c0f77297a29bbc262de093b1072f2fc17ee048a81

There are just part of the transactions failed, we want to know why

2 Answers 2


The attached fee is too small. How are you creating your transactions? If you're using the cardano serialization lib (from here https://github.com/Emurgo/cardano-serialization-lib) and you're using the add_change_if_needed function, call it right before building the tx to make sure it adds the right fee.

Often times while testing you can have single pure Ada UTXOs as inputs and outputs and when you go live you can get fragmented multiple UTXOs to cover the required sum with various assets attached etc., which can cause the fee to vary depending on the total tx size. Depending on the coin selection strategy the mechanism for choosing UTXOs can be random, which is why it only sometimes occurs.

  • Yes I used cardano serialization lib, and my add_change_if_needed is just right before building the tx
    – Eric Tsai
    May 18, 2022 at 8:04
  • txBuilder.add_change_if_needed(this.S.Address.from_bech32(PaymentAddress)); const transaction = this.S.Transaction.new( txBuilder.build(), this.S.TransactionWitnessSet.new(), AUXILIARY_DATA );
    – Eric Tsai
    May 18, 2022 at 8:06
  • We calculate the fee and build the transaction in the frontend, then the backend sign and submit the tx, would that be the problem for the wrong tx fee?
    – Eric Tsai
    May 18, 2022 at 8:14
  • That should not be a problem. Creating a tx on the frontend and signing on the backend generally should be fine, but there seems to be a change in tx size happening somewhere, it could be somewhere in the cbor encoding / decoding processes. Maybe this helps: developers.cardano.org/docs/get-started/…
    – sean
    May 18, 2022 at 17:58

Just set your fee to 272465 and resubmit the tx, then you should be fine

  • There are different utxo fee, if I just simply set to 272465, the tx exceeding 272465 will fail, unless I set it to 500000
    – Eric Tsai
    May 18, 2022 at 16:24
  • How are you building your transactions? Because if you're using the cardano cli you can let the cli calculate the fee instead of manually inputting it. Same can be done using the cardano-serialization library
    – Will
    May 18, 2022 at 16:29

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