I am still confused about whether it is still a valid transaction for multiple output transactions if the total output of the transaction exceeds the amount of total input.

For example, there are two inputs in Bitcoin transactions, one having a value of 1.5BTC and one of 0.75BTC, and two outputs, one with a value of 1.3BTC and one of 1.25BT.

Is this a valid transaction? And how about the transaction fee? Because one output is still less than the size of some of the input or the total input.

1 Answer 1


No, it is not. The individual values of the inputs and outputs don't matter, only the sum matters. So the sum of the inputs is compared against the sum of the outputs. And since the sum of the outputs is greater than the sum of the inputs, the transaction is invalid.

Bitcoin does not take Bitcoin from particular inputs and map it to a particular output. Instead it's like all inputs in the transaction get mixed together, and then that total amount is split out into outputs and fees. So only the sum matters.

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