Definition
Busy season is the period when audit and tax deadlines cluster. For calendar-year clients, audit fieldwork and report issuance run from about January to March, while partnership and S corporation returns are due March 15 and C corporation and individual returns April 15 for calendar-year filers. Extended returns create a second peak around September 15 and October 15. Employee benefit plan audits also feed the fall peak because the extended Form 5500 date is October 15.
Why it matters in an audit or review
Overload can hurt quality. Fatigue, thin review time and rushed sampling are the obvious risks. Firms plan by staggering year-end clients, fixing PBC due dates in the engagement letter, scheduling interim work, and limiting staff overtime. Clients that deliver PBC items late push work into the peak and raise fees.
Example
Illustrative: a firm schedules interim control testing for a manufacturer in November and agrees a firm PBC due date of January 15 with each client, so the final fieldwork team has fewer concurrent engagements.
Common mistakes
Accepting more calendar-year audits without increasing review capacity.
FAQ
Is there a busy season outside tax time?
Yes. Fall brings extended returns and benefit plan filings, and entities with June 30 year ends, such as many governments and universities, are audited then.
Sources
- IRS, filing due dates for Forms 1065, 1120-S, 1120 and 1040, and Form 7004 extensions (IRC Section 6081)
- US Department of Labor, EBSA, Form 5500 Series instructions (due date and Form 5558 extension, which gives 2.5 months)
- 2 CFR 200.512(a), Report submission (Single Audit due within nine months of year end), https://www.ecfr.gov/current/title-2/subtitle-A/chapter-II/part-200/subpart-F/subject-group-ECFR4424206eb6d5f12/section-200.512
Definitions paraphrase AICPA and FASB guidance; read the standard itself before relying on a requirement. Example figures are illustrative. This page is guidance, not professional advice. Report an error