Nudging businesses to pay their taxes: Does timing matter?

•This paper studies the effect of varying the timing of reminder letters on the tax payment behavior of small businesses.•We provide an overview of the theoretical and empirical literature on tax compliance and reminders.•A field experiment reveals that a simple reminder letter increases the probability of payment by about 25 percentage points.•Variation over a three-week period in the timing of the reminder letter has no effect on the probability of payment.•Sending reminders early results in faster payment of debts with no effect on the ultimate probability of payment.