Normally, a transaction output will contain a list of address + amount. Each element in this list has an associate output number, "vout". For example:

Transaction outputs:

vout=0: addr=m111111, amount=100 
vout=1: addr=m222222, amount=200

My question is: would it be legal for a transaction output to contain the same target address more than once? Take for instance the example below, where address "m222222" appears in vout=1 and vout=2:

vout=0: addr=m111111, amount=100
vout=1: addr=m222222, amount=100
vout=2: addr=m222222, amount=100

I know this seems silly. I'm just wondering if it is the sort of thing one might encounter "in the wild".

1 Answer 1


There is no protocol rule which forbids having multiple outputs with the same bitcoin address. Here is an example of such a transaction:


It is not common to see this as there is no point in having mutiple outputs when it can be done in one, it just makes the transaction larger and hence increases transaction fees.

  • In fact, there really couldn't be such a protocol rule because bitcoin addresses aren't protocol-level structures. They're just convenient ways for humans to refer to the keys used to claim transaction outputs. Two transaction outputs that happen to be claimable with the same key would just appear to be two valid transaction outputs to the protocol. Commented Aug 20, 2012 at 0:19

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