During data entry tasks, small errors can result in catastrophe, for instance adding an extra zero to a drug dose when programming an infusion in a hospital. For this reason understanding users’ error checking behavior is highly important. One aspect that can affect error checking is the interface that a user must interact with to enter data. Often user interaction with interfaces is evaluated based on speed or error rate. In this paper, in addition to this, we also explore how different types of interface can affect a user’s error checking behavior in a multitasking environment. We show that a fast to use and familiar interface discourages users from carrying out thorough visual checking in a number transcription task. We also found that having participants perform an additional secondary task while doing the number entry task made participants less likely to check the inputted numbers for errors.