# Concepts ## Acknowledgements ICS20 uses the recommended acknowledgement format as specified by [ICS 04](https://github.com/cosmos/ics/tree/master/spec/ics-004-channel-and-packet-semantics#acknowledgement-envelope). A successful receive of a transfer packet will result in a Result Acknowledgement being written with the value `[]byte(byte(1))` in the `Response` field. An unsuccessful receive of a transfer packet will result in an Error Acknowledgement being written with the error message in the `Response` field.