I am trying to follow these instructions.

I do not want to sync so I run

./geth-1.9.0 --maxpeers 0 console`

and do this:



TX={ from: FROM, to: TO, value: VALUE, nonce: NONCE }


I get this error

WARN [06-30|20:58:39.016] Served eth_sendTransaction               reqid=36 t=5.238384ms   err="gas required exceeds allowance (5003) or always failing transaction"
Error: gas required exceeds allowance (5003) or always failing transaction
    at web3.js:3143:20
    at web3.js:6347:15
    at web3.js:5081:36
    at <anonymous>:1:1

How do I figure out if the error is "gas required exceeds allowance" or "always failing transaction"?

How do I figure out what the required gas amount and allowance amounts are?

What went wrong?

  • provide more gas value during transaction building
    – Badr Bellaj
    Jun 30, 2019 at 20:48
  • 1
    How? And how much?
    – spraff
    Jul 1, 2019 at 9:42

1 Answer 1


try to define enough gas in your TX

TX={ from: FROM, to: TO, value: VALUE, nonce: NONCE , gas: 3000000 }

keep rising the gas value until it works.

  • I'm confused between "gas", "gas price", and "gas limit". ethgasstation.info says 1Gwei is "standard", you wrote 3Mwei in your example so I'm wondering if it means the same thing. Does the gas property here refer to price, limit, or something else?
    – spraff
    Jul 1, 2019 at 22:00
  • gas : is The amount of gas to use for the transaction (unused gas is refunded)in other words it's the gas you'are wiling to pay for you transaction. Please check the doc github.com/ethereum/wiki/wiki/…
    – Badr Bellaj
    Jul 2, 2019 at 21:07
  • In many places elsewhere I read that "gasUsed=gasPrice*gas" but if unused "gas" is refunded then that usage of "gas" would seem to refer to a limit on "gasUsed" whereas "gas" in the equation would seem to refer to another kind of quantity, measured in a different dimensional unit. Right?
    – spraff
    Jul 7, 2019 at 13:19
  • I mean, if "gasPrice" is measured in wei/some_unit and "gas" is measured in some_unit then "totalGas=gasPrice*gas" is measured in wei which makes sense but what on earth are the units for this "gas" parameter? Because it sure as hell isn't in wei.
    – spraff
    Jul 7, 2019 at 13:23

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