incidental

Not of prime or central importance.

Occurring with or following as a consequence.

“snags incidental to the changeover in management”

(sometimes followed by `to') minor or casual or subordinate in significance or nature or occurring as a chance concomitant or consequence.

“incidental expenses”

“the road will bring other incidental advantages”

(frequently plural) an expense not budgeted or not specified.

“he requested reimbursement of $7 for incidental expenses”

An item that is incidental.