reimburse (one) for (something)
To give one back the money that one has spent on something, typically when one did so at the behest of someone else. You'll have to cover your own expenses on the trip, but just bring back your receipts and we'll reimburse you for them once you're back at the office. Would you mind paying the bill tonight? I can reimburse you for it later!
reimburse someone for something
to repay someone for making a purchase, such as a business expense. I will reimburse you for whatever it cost you. The treasurer reimbursed himself for his expenses.