Post-Tax-Season Review: What to Audit Now That the Rush Is Over

April 16th passed. Extensions are filed. Your team is taking a breath for the first time in weeks. The natural instinct right now is to decompress, maybe take a long weekend, and not think about deadlines for a while.

That instinct is understandable, but this window between mid-April and the end of May is actually the most valuable time on your firm's calendar for something that gets pushed aside every single year: a security review.

Not because something went wrong. Because tax season, by its nature, creates conditions that erode security. Temporary staff gained access to systems. Passwords were shared under time pressure. Software permissions expanded to keep things moving. Remote access was extended to people who needed flexibility during the crunch. All of these decisions made sense in the moment. The question now is whether any of them created a gap that's still open.

Why the Post-Season Window Matters

The IRS received over 250 data breach reports from tax professionals in 2024, impacting more than 200,000 clients. Many of those breaches didn't happen because of one dramatic failure. They happened because small operational decisions during the busiest weeks of the year accumulated into exploitable gaps.

Tax season is a period of elevated risk for every accounting firm. Accounting firms face an average of 900 cyberattack attempts during tax season alone, and phishing attempts targeting tax professionals spike by as much as 300% between January and April. Your firm probably weathered all of that successfully. But "we got through it" is not the same as "we're still buttoned up."

The FTC Safeguards Rule requires periodic reassessment of your information security program based on changes to your operations, emerging threats, or changes in personnel. Tax season involves all three. The regulatory expectation is that your program adapts when your operating conditions change. And they just changed significantly for three straight months.

The Five Areas That Drift During Tax Season

1. Temporary and Seasonal Staff Access

You brought on seasonal preparers. They needed email, tax software access, maybe the client portal. The question now: are those accounts still active?

One of the most common post-season gaps is access that outlives the person who needed it. A departed seasonal employee with an active login becomes an orphaned credential. If that credential is compromised through a phishing attempt or a password reuse from a personal breach, an attacker can walk into your systems months from now, and it will look like legitimate access.

Action: Run a complete user access audit across every system. Email, tax software, document management, VPN, client portals. Disable every account that belongs to someone no longer working at the firm. Do it this week, not next month.

2. Permissions That Expanded Under Pressure

During the rush, someone needed access to a client folder they don't normally touch. Someone else needed admin rights to troubleshoot a software issue. A partner gave a staff member access to their email to handle a client request while they were on a call.

These temporary expansions have a tendency to become permanent. The access was granted, the problem was solved, and nobody went back to revoke it. Three months from now, people have access they shouldn't have, and nobody remembers why they got it in the first place.

Action: Review access permissions on your critical systems. Compare who has access today against what each person actually needs for their current role. Reset anything that was expanded for tax season purposes.

3. Devices and Remote Access

If your team worked remotely during tax season, or if anyone used a personal device to access firm systems, you need to verify that those access points are still controlled. Were personal laptops used to download client files? Is remote desktop still open for someone who no longer needs it? Was a VPN connection extended to a device that's now sitting on someone's home network without endpoint protection?

Action: Work with your IT provider to review all active remote connections. Close any VPN tunnels or remote desktop sessions that are no longer needed. Confirm that any personal devices used during tax season have been properly wiped of client data.

4. Password Hygiene

Tax season puts pressure on everything, including password discipline. Under time constraints, people reuse passwords, share credentials, or skip multi-factor authentication prompts because they're trying to get through a queue of tasks. One in five data breaches starts with compromised credentials, and credential fatigue is highest after long periods of intense work.

Action: Require a password reset for all staff on key systems. Check Have I Been Pwned against your team's email addresses. If any credentials appear in known breaches, change them immediately and confirm that multi-factor authentication is enforced on every account.

5. Documentation Gaps

During the rush, documentation is the first thing that slips. Training records don't get updated for new hires. Security incidents or near-misses don't get logged. Policy exceptions don't get noted. The problem isn't that these gaps exist during tax season. The problem is that if you don't close them now, you'll have a compliance hole when a regulator asks about your program.

IRS Publication 4557 requires that your Written Information Security Plan be reviewed and updated regularly, with documentation of changes, security events, and training activities. The post-season window is the right time to update that documentation while the details are still fresh.

Action: Update your WISP with any changes that occurred during tax season. Document the access you granted, the training your seasonal staff received (or didn't receive), and any security incidents or suspicious activity that was reported.

Make It a Recurring Calendar Event

The best version of this isn't a one-time exercise. It's a standing post-season review built into your firm's annual calendar. Every year, the third week of April (or whenever your firm's busy season officially ends), you block two hours with your office manager and your IT provider and walk through the same checklist.

Talk to your IT provider about what they observed during tax season. Did they see any unusual login activity? Were there any blocked threats worth reviewing? Did any systems flag performance issues that might indicate unauthorized access? Your IT partner has visibility into things you don't, and this is the right time to compare notes.

The NIST Cybersecurity Framework recommends periodic reassessments tied to operational changes. The FTC Safeguards Rule requires it. And common sense supports it. Tax season is the most operationally intense period for your firm. The security review that follows it should be proportional.

What You Can Do This Week

1. Run a user access audit. List every account on every system. Disable anything belonging to someone no longer at the firm.

2. Review expanded permissions. Identify any access changes made during tax season and revert anything that's no longer justified.

3. Close remote access gaps. Work with your IT provider to shut down VPN connections, remote desktop access, and personal device access that was extended for the busy season.

4. Reset passwords on critical systems. Require a fresh password for email, tax software, and client portals. Enforce multi-factor authentication across the board.

5. Update your WISP. Document what happened during tax season: new hires, access grants, training delivered, incidents observed. This documentation is your evidence that you manage your program actively.

The Bottom Line

Tax season is over, but the security decisions you made during it are still in effect. The access you granted, the shortcuts you took, the documentation you deferred. All of it is still sitting there, waiting for either you or an attacker to notice.

This isn't about being paranoid. It's about being thorough. The firms that conduct a disciplined post-season review close gaps before they become problems. The firms that don't will spend the rest of the year hoping nothing slipped through.

If you want a structured way to run this review across your entire firm, SafeGuardGRC can help you build the checklist, coordinate with your IT provider, and document everything for compliance. But even without a tool, the checklist above is something you can start today.

Your team earned the rest. Your systems haven't.