'by commission' is correct and can be used in written English.
An example sentence would be: "The artwork was created by commission to commemorate the anniversary."
NSC — Cap getting ready to release study by commission investigating Beirut massacre of our Marines (241).
The fine, though large by commission standards, is small for Google.
Henszey & Albert uses a straight fee system; of its 16 clients, only one pays by commission.
Atomic energy, human rights, a free press and civil liberties will never become universal by commission.
Salespeople were paid by commission for centuries before economists began writing about the principal-agent problem.
Traditionally architects work by commission, designing what they are paid to design.
Penhaligon, by the way, has long been the come-hither-by-commission spray of fancy male decorators everywhere.
Borrowers get too easy a ride: not all of them were unsophisticated types, duped by commission-obsessed brokers.
They are vastly outnumbered by commission-generating stockbrokers, annuity salesmen and life insurance agents.
The validation was performed following the criteria established by Commission Decision 2002/657/EC.
The capacity factor k′ of the first eluting analyte (DON) is >1 (actually 1.5), a criteria set by Commission Decision 2002/657/EC [ 36].
