.webp)
Microsoft 365 has become the backbone of modern law firms, accounting practices, and financial institutions. But while most firms rely on M365 every day, few are using it to its full potential — and even fewer are managing it in a way that is truly secure, compliant, and cost‑efficient. As we move deeper into 2025, it’s clear that professional services firms need more than a basic M365 setup. They need governance, automation, and visibility across the entire environment.
Here are the best practices every firm should implement to keep their data protected and their operations running smoothly.
1. Conduct Regular User Access Reviews
User sprawl is one of the biggest hidden risks within Microsoft 365. Employees leave, roles change, permissions get added “temporarily,” and before long, the firm has users with excessive access — or worse, active accounts no one realized were still open.
What firms should do:
- Review user access quarterly (at minimum)
- Remove or restrict unused accounts
- Enforce role-based access
- Audit mailbox, SharePoint, and OneDrive permissions
For firms handling confidential client data, this isn’t optional. It’s a fundamental control for security and compliance.
2. Implement Strong Retention & Deletion Policies
Many firms either keep everything forever or delete nothing at all — both approaches create risk.
Proper retention policies help with:
- Litigation readiness
- E-discovery efficiency
- Data privacy compliance
- Reducing storage bloat and cloud costs
Key M365 features to configure:
- Retention labels
- Retention policies for email, Teams, and SharePoint
- Automatic deletion rules
- Litigation hold (only when necessary)
These policies ensure your firm keeps what it’s legally required to — and safely removes what it shouldn’t keep.
3. Secure External Sharing
Attorneys, accountants, and advisors share documents constantly. But unrestricted external sharing is a major source of data leaks.
Best practices:
- Disable anonymous sharing
- Require authentication for all shared files
- Use time-bound sharing links
- Restrict sharing to approved domains
- Review external users regularly
With the right controls in place, your team can collaborate securely without exposing sensitive client information.
4. Optimize Cloud Licensing and Storage
One of the most overlooked opportunities in M365 is cost optimization. Many firms overpay for unused licenses or underutilized features simply because no one is monitoring usage.
Steps to save costs:
- Identify unused or inactive licenses
- Remove redundant add-ons
- Consolidate plans where appropriate
- Review OneDrive and SharePoint storage consumption
- Explore built-in security tools before paying for third-party solutions
Most firms can reduce their M365 spend by 10–25% with a simple optimization review.
5. Strengthen Security Baselines
Out-of-the-box M365 is not secure enough for legal, accounting, or financial environments. Every firm should implement a hardened baseline that includes:
- Mandatory MFA
- Conditional access policies
- Device compliance policies (especially for mobile)
- Email authentication (DKIM/DMARC/SPF)
- Endpoint monitoring
- Zero-Trust-aligned identity configurations
These controls dramatically reduce the risk of credential theft and unauthorized access.
How TEKMARK Helps
TEKMARK specializes in optimizing Microsoft 365 environments for law firms, accounting practices, and financial institutions. We help firms:
- Configure secure access controls
- Build retention and deletion policies
- Optimize licensing and reduce costs
- Implement secure external sharing controls
- Align M365 with SOC 2, HIPAA, and GLBA requirements
- Establish continuous monitoring and governance
Whether your firm needs a one-time audit or ongoing management, our team ensures your M365 environment is secure, efficient, and compliant. Microsoft 365 is powerful — but only if it’s configured with intention. If your firm is ready to modernize its M365 environment, TEKMARK is here to help you get it right.