交费 is a verb-object compound (离合词) meaning 'to pay a fee or charge'. The verb 交 and the object 费 can be split when you need to insert a measure word, duration, or other modifier, for example: 交了一个月的费 ('paid a month's fee') or 交过两次费 ('paid the fee twice'). When not split, it's used like a regular verb with the fee amount or purpose placed after the whole word (e.g. 交费一百元).