We use data from an online financial service to show that many consumers fail to stick to their self-set debt paydown plans. This behavior is best explained by present bias. Our empirical approach is informed by a parsimonious model showing that the sensitivity of spending to paycheck receipt reflects a present-biased agents short-run impatience, and that this sensitivity is reduced by available resources only for agents who are aware (sophisticated) of their future impatience. Classifying users accordingly, we find that (i) sophisticated users debt paydown decreases with short-run impatience, and that (ii) planned paydown is most predictive of actual paydown for sophisticated users.