The Hidden Cyber Risk Window After Tax Season

Tax season is behind you. You met the filing deadline, and your team can finally relax. But while most businesses see April 15 as a finish line, cybercriminals see it as an opportunity. The good news? Your returns are in. The part to keep on your radar? Cyber risk doesn't drop on April 15, it shifts. And with a little awareness, your business can stay a step ahead.

That In-Between Period After Filing? Not As Quiet As It Seems.

It's natural to feel like the hard part is over once the filing deadline passes—and in many ways, it is! But threat activity often spikes in the weeks right after tax season ends. Refunds are still in transit, a little uncertainty lingers, and your team has earned a well-deserved exhale after months of financial deadlines. Cybercriminals know all of this and they count on it.

According to Infosecurity Magazine, researchers have identified more than a hundred distinct malicious campaigns running around tax deadlines and many of them are specifically built to keep running after the filing deadline, during that quieter stretch when most people have mentally moved on. These range from simple phishing emails to more coordinated attempts to access financial systems or steal data.

Because the IRS typically takes weeks to process returns and issue refunds, that window of uncertainty is a playground for social engineering. Businesses expect follow-up emails and notices, which is exactly what makes it tricky to spot the ones that aren't legitimate

A New Wave of Scam Themes Arrives After April 15

One of the more useful things to know is how scam messaging tends to evolve after the filing deadline. Before April 15, phishing attempts usually play on urgency around filing itself—things like "You haven't filed yet" or "Act now to avoid penalties." After the deadline, the messaging shifts to sound more like routine follow-up:

Now the hooks look like this:

• "There's an issue with your refund."
• "Your return has been flagged for review."
• "Additional documentation is required to process your submission."
• "Your refund has been delayed—action required."
• "We were unable to verify your identity. Please confirm your information."
• "Your tax filing is under audit—respond within 48 hours."

These messages can feel convincing precisely because they fit the moment. Your team just went through a major financial process so of course there might be some follow-up. The IRS notes that messages referencing penalties, missing documents, or compliance issues tend to prompt quick reactions, often before anyone stops to verify whether they're real.

Here's some helpful context on just how active this threat has become. The IRS Criminal Investigation unit recently uncovered $9.1 billion in tax fraud and financial crimes in a single year, with nearly 2 million tax returns flagged for identity theft totaling $16.5 billion in fraudulent filings. Monthly tax scam reports have climbed more than 323% since 2020, and the 2026 BBB Scam Tracker data shows a 62% jump in just one year alone. The FTC's consumer protection bureau has also noted that robocalls, texts, and phishing emails are on the rise with AI making these attempts look more convincing than ever.

Why Businesses Are More Vulnerable After Tax Season

Sensitive financial data is still sitting around.

During tax season, your business accumulates a significant volume of sensitive financial information: payroll records, W-2s, bank account details, employee social security numbers, vendor payment data, etc. Once the returns are filed, that data doesn't always get cleaned up right away. It lingers in email threads, shared folders, and temporary storage. The FBI's IC3 reported more than 1,000 complaints about identity theft connected to tax returns in the past year alone—a 26% increase from the prior year much of it tied to exposed financial data.

Temporary access often isn't revoked.

Tax season typically brings in outside help: accountants, bookkeepers, payroll vendors, or contractors—all of whom need some level of access to your systems. Once April 15 passes, revoking that access can often fall to the bottom of the to-do list. According to Proofpoint Research, attackers specifically look for these open access channels, sometimes impersonating executives to request W-2 and W-9 forms through the same pathways your vendors already use.

Many businesses don't have the right tools in place to catch threats automatically. Without proper email filtering, endpoint monitoring, or security alerting, post-filing scams can slip through unnoticed, especially when they're disguised as routine tax correspondence. According to the 2025 Verizon Data Breach Investigations Report, 60% of breaches involved the human element. If your business doesn't have baseline protections like multi-factor authentication, email security filtering, and access monitoring in place, the post-tax window is a great time to revisit that conversation.

The cybersecurity expertise gap: especially for SMBs

Many small and mid-sized businesses don't have dedicated cybersecurity expertise in-house, and that gap leaves them more exposed than they realize. According to IBM's Cost of a Data Breach Report, more than half of breached organizations experienced severe security staffing shortages, and the lack of trained security personnel contributed to an average increase of $1.76 million in breach costs. The World Economic Forum reports that nearly 90% of organizations experienced a breach they can partially attribute to a cybersecurity skills gap. Having the right expertise in your corner, whether in-house or through a trusted IT partner, can make all the difference.

The importance of cybersecurity training for employees

Most people want to do the right thing when it comes to security. The challenge is that the threat landscape has changed dramatically, and traditional once-a-year training just hasn't kept pace. According to Fortinet's 2025 Security Awareness and Training Report, nearly seven in ten business leaders say their employees still lack sufficient security awareness, even at organizations that do have a training program in place. The issue often isn't whether training exists, but whether it's current, engaging, and reinforced regularly enough to stick.

The Good News: Consistent Training Works

Organizations that implement regular security awareness programs can significantly reduce phishing susceptibility. The SANS Security Awareness Report states that social engineering, including phishing, accounts for 89% of human risk concerns, and the most effective defense is a well-structured, ongoing training program. Organizations that treat training as a continuous practice rather than a one-time event see measurably stronger security outcomes. Modern training doesn't have to be a long, dry annual presentation; short, frequent, and scenario-based modules are far more effective at building the kind of instinct that helps employees recognize a suspicious “refund flagged” email before they click it.

Takeaways for Business Leaders

Here's a framework worth keeping in mind:

Peak volume: during tax season. Peak vulnerability: immediately after.

That's why late April and May should be treated as a cleanup risk window, not a rest period. For business leaders, that means taking a few deliberate steps right now:

1. Audit and revoke temporary access. Take a few minutes to check which outside accountants, contractors, or vendors still have access to your systems and remove what's no longer needed. It's easy for these permissions to linger well past their purpose, and every open access point is an opportunity an attacker can exploit. A quick access audit now can close doors you didn't even realize were still open.
2. Purge or secure sensitive financial data. W-2s, bank records, SSNs, and other tax documents should be stored securely or purged according to your retention policy, not left sitting in shared drives or email threads where they're easy to find. Think about where that data lived during tax season and make sure it's either locked down or cleaned up. The less sensitive data floating around, the smaller your exposure.
3. Watch for W-2 and W-9 requests. Business email compromise campaigns specifically target businesses with fake executive requests for tax forms in the post-filing period. The IRS warns businesses to be especially wary of fraudulent W-2 requests now that the filing deadline has passed.
4. Make sure the right cyber tools and people are in place. Email filtering, endpoint monitoring, multi-factor authentication, and access controls are the foundation, but they're only as effective as the people managing them. If your business doesn't have an IT professional or a partner with real cybersecurity expertise, now is a great time to have that conversation. The post-tax window is a good reminder that reactive security isn't enough.
5. Give your employees a quick heads-up. Let them know that "refund issue" or "return flagged" messages are a common post-filing scam theme right now. People are naturally more likely to engage with tax-related emails in the weeks after filing, which is exactly what makes these lures so effective. Of course, the strongest line of defense will always be users who’ve undergone consistent cyber security training, (see #6!)
6. Invest in regular, modern cybersecurity training for your team. A one-time orientation isn't enough in today's environment. Short, frequent, scenario-based training helps employees build the instincts to recognize suspicious emails—especially the post-filing lures that feel so convincing this time of year. It's one of the highest-return investments a business can make in its own protection.

The average cost of a data breach now sits at $4.88 million per incident, and phishing-related breaches take an average of 254 days to fully identify and contain. A little proactive housekeeping this week is well worth the effort. You've done the hard work of getting through tax season. A few small steps now can go a long way toward keeping your business protected.

For real-time scam alerts and fraud reporting, visit IRS.gov/scams and report suspicious IRS-related communications to phishing@irs.gov.

Want to make sure your business has the right tools, training, and cybersecurity expertise in place to stay protected? Reach out to Uprise's cybersecurity experts—we’re here to help!