Address that can pay "commission"? There is a use case where person A needs to send person B, .9 BTC.  Person C, who set up the transaction, should get .1 BTC as commission.
I know this is possible to do with a traditional &quot;bitcoin wallet&quot; by creating a transaction with two payees.  The problem is that for usability reasons, the payment needs to be &quot;bip-21&quot; compatible, which basically means it has to be of the form bitcoin:&lt;address&gt;[?amount=&lt;amount&gt;][?label=&lt;label&gt;][?message=&lt;message&gt;] which only allows for one output address.
So my question is, is there a way to make some &quot;intermediary&quot; address that will forward .9 to A and .1 to C?  Or is there some other way to do this within the constraints of bip-21?
This is not possible.
The Bitcoin protocol (currently) has no affordances to control what a recipient can do with coins they receive.