CPA firms are expected to meet 7–9 core IT security and compliance requirements to properly protect client financial and tax data. One of the most critical—and commonly overlooked—requirements is maintaining a Written Information Security Policy (WISP), which the IRS explicitly requires for firms that handle taxpayer information. Alongside a WISP, CPA firms typically need multi-factor authentication (MFA), email security, endpoint protection, secure backups, access controls, and ongoing monitoring. For CPA firms with 10–50 employees, missing even one of these controls can increase breach risk by 2–3×, especially during tax season.
Below is a practical breakdown of what CPA firms are expected to have in place—and why it matters.
Core IT Security and Compliance Requirements for CPA Firms
CPA firms are not regulated exactly like banks or healthcare providers, but they are subject to IRS safeguards and client confidentiality obligations that require documented, enforceable security controls.
1. Written Information Security Policy (WISP) — IRS Requirement
The IRS requires CPA firms to maintain a Written Information Security Policy (WISP) under the Safeguards Rule for anyone who accesses or processes taxpayer data.
A compliant WISP should:
- Document how client data is protected
- Define administrative, technical, and physical safeguards
- Assign responsibility for security oversight
- Address risk assessment and mitigation
- Be reviewed and updated regularly
A WISP is not optional, and it is not a one-page template. Firms without a current WISP are exposed to compliance risk, even if no breach has occurred.
2. Data Protection and Access Control
CPA firms must strictly control who can access client financial and tax data.
This typically includes:
- Role-based access to files and applications
- Multi-factor authentication (MFA) for email, cloud apps, and remote access
- Strong password standards and account lockouts
Access controls should be documented in the WISP and enforced technically across systems.
3. Email Security and Phishing Protection
Email is the primary attack vector for CPA firms, particularly during tax season.
Security best practices include:
- Advanced spam and phishing filtering
- Protection against spoofed IRS and client emails
- User security awareness training
- Alerts for suspicious logins or forwarding rules
Many IRS-related breaches begin with a single phishing email.
4. Endpoint Security and Device Management
Every device that accesses client data must be secured and managed.
CPA firms should require:
- Managed antivirus or EDR (endpoint detection & response)
- Automated patching for operating systems and applications
- Full-disk encryption on all laptops and desktops
Lost or unencrypted devices can quickly become reportable incidents.
5. Backup, Retention, and Disaster Recovery
Secure backups are a core compliance and business continuity requirement.
Best practices include:
- Encrypted backups stored offsite or in the cloud
- Defined data retention periods (commonly 30–90+ days)
- Regular testing of backup restores
- Documented recovery time objectives (RTOs)
Backup and recovery expectations should also be documented within the WISP.
6. Monitoring, Logging, and Incident Response
Security controls are ineffective without active monitoring and response.
CPA firms should have:
- 24/7 system and security monitoring
- Logging of access and security events
- A documented incident response plan
IRS expectations include the ability to detect, respond to, and document security incidents.
How IRS Compliance Impacts CPA Firms Specifically
CPA firms that handle taxpayer data are expected to:
- Protect data under IRS Safeguards requirements
- Maintain written security policies (WISP)
- Limit access to authorized users only
- Respond appropriately to security incidents
Failure to meet these expectations can lead to client risk, reputational damage, and potential IRS scrutiny, even if no data loss occurs.
Example: Security Setup for a 20-Person CPA Firm
A typical 20-employee CPA firm in Chicago should have:
- A documented and maintained WISP
- MFA on all email, cloud, and remote access
- Encrypted laptops and desktops
- Advanced email security
- Secure backups with 30–90 day retention
- 24/7 monitoring and alerting
This setup aligns with IRS expectations and significantly reduces breach and downtime risk.
Why WISP and Security Gaps Are Especially Risky for CPA Firms
CPA firms without a WISP or documented controls often face:
- Compliance exposure during audits or client reviews
- Increased risk of ransomware and phishing attacks
- Downtime during filing deadlines
- Difficulty proving due diligence after an incident
Many firms assume security tools alone are enough—but documentation matters.
What CPA Firms Should Look for in an IT Provider
CPA firms should work with IT providers that:
- Understand IRS safeguard requirements
- Help create, maintain, and review a WISP
- Implement and enforce documented controls
- Provide proactive monitoring, not just reactive fixes
- Understand CPA workflows and tax season pressure
Security is both technical and procedural—and both must be addressed.
Final Thoughts
CPA firms are expected to meet real, documented IT security and compliance standards—not just “best effort” IT support. A Written Information Security Policy (WISP), combined with strong technical controls and proactive monitoring, is foundational to protecting client data and meeting IRS expectations.
For CPA firms, IT security isn’t just about avoiding breaches—it’s about compliance, trust, and uninterrupted operations during critical deadlines.