The best thing to do is to pay your loan off on your next pay date as originally agreed with your lender. If you default then you may be subject to fees (NSF), collections activity, and in some limited cases, legal actions. Again, these vary by the state you live in. You should never accept a loan offer unless you know you can pay it off as agreed upon in advance. Paying off your loan on time also can help you start to build your credit or improve it.