The SEC requires that firms failing to file their annual reports within the specified deadlines file a Form NT 10−K with the Commission. In this paper, we examine the impact of non-timely filings on audit fees. We find that in the case of accelerated filers, audit fees are 26 (12) percent higher for those firms that had a Form NT 10-K filing in the previous (current) year. There is no such statistically significant association between non-timely filing and audit fees in the case of non-accelerated filers, but this result is driven by the clients of non-Big 4 auditors. Our results add to the stream of research related to non-timely filings of annual reports, and provide additional evidence about differences in audit quality/risk between Big 4 and non-Big 4 audit firms. The results also reinforce findings from recent studies about the significant differences in the market for audit services of accelerated and non-accelerated filer firms.