Chapter 13 is designed to pay debt over a set period of time. In most cases, that won’t decrease if you have more disposable income than you expected. However, the court will allow you to pay off your bankruptcy plan early if you pay creditors 100% of their claimed amounts (some unsecured creditors don’t file claims and you don’t normally have to pay those debts). If you are able to pay all of your outstanding debt, specifically, those creditors that actually filed claims, then you could pay off your plan early.