Microsoft 365 is central to the daily work of many accounting firms. Email, Teams, SharePoint, OneDrive, calendars, and client documents may all be connected to the same cloud identity. This improves collaboration, but it also means that one compromised account can expose several business systems at once.

Accounting practices need controls that protect confidential financial information while allowing employees to work efficiently during tax season, audits, payroll deadlines, and remote client engagements. The right configuration combines identity protection, controlled sharing, device security, monitoring, and reliable backup.

Start with strong identity protection

Every user should have a unique account protected by multi-factor authentication. Shared sign-ins reduce accountability and make it harder to remove access when responsibilities change. Legacy authentication should be disabled, administrator privileges restricted, and emergency administrative access protected separately.

Conditional Access can apply stronger rules when a sign-in originates from an unfamiliar location, unmanaged device, or risky session. These protections are most effective when they are designed around the firm’s actual workflow. Our IT support for accounting firms helps practices configure Microsoft 365 without creating unnecessary obstacles for staff.

Secure email against financial fraud

Business email compromise is particularly dangerous for accountants because attackers can imitate payment instructions, payroll changes, document requests, and messages from partners or clients. Microsoft 365 security policies should include anti-phishing protection, safe attachment and link analysis, impersonation controls, and monitoring for suspicious forwarding rules.

Staff should verify changes to banking or payment details through a trusted channel. SPF, DKIM, and DMARC also help reduce unauthorized use of the firm’s domain. For the wider threat picture, see cybersecurity risks facing Vancouver accounting firms.

Control SharePoint and OneDrive sharing

Client files should be shared only with the intended people and for an appropriate period. Anonymous links, unrestricted external sharing, and permanent access can create unnecessary exposure. Firms should establish standard client folders, named-user sharing, expiration dates, and regular access reviews.

Sensitivity labels and data-loss prevention policies can help identify and control confidential information such as financial records, tax documents, identification numbers, and banking details. These controls should be tested carefully before broad deployment.

Protect every device

A secure cloud account is not enough if the computer accessing it is unprotected. Workstations and laptops should use encryption, endpoint detection and response, automatic patching, screen-lock policies, and managed antivirus protection. Lost or stolen devices should be removable from the organization and, where supported, remotely wiped.

Remote staff should avoid storing client files on personal computers or unapproved USB devices. Managed devices provide better visibility and consistent security. SOS Computer Experts combines these controls through our cybersecurity services and managed IT services.

Back up Microsoft 365 separately

Microsoft provides a resilient cloud platform, but firms remain responsible for access, retention, accidental deletion, malicious deletion, and many recovery requirements. A separate backup protects Exchange Online, OneDrive, SharePoint, and Teams information and gives the firm additional recovery options.

Backups should be automated, monitored, retained appropriately, and tested. Our backup and disaster recovery solutions help protect Microsoft 365 alongside QuickBooks files, servers, and other critical systems. Read the related guide to backup and disaster recovery for accounting firms.

Review permissions and activity

Access should reflect each employee’s responsibilities. Departing users should be disabled promptly, and guest accounts should be reviewed regularly. Audit logs, risky sign-ins, mailbox rules, administrator changes, and unusual downloads can provide early warning of an incident.

Accounting firms in Vancouver can benefit from a local partner that understands both Microsoft 365 and professional-services security. Our Vancouver managed IT services support cloud administration, endpoint management, security monitoring, and user support.

Plan the next security improvements

A Microsoft 365 review should examine identity settings, administrator roles, email protection, external sharing, device compliance, audit visibility, and backup coverage. The result should be a prioritized roadmap rather than a generic checklist.

Contact SOS Computer Experts for a Microsoft 365 security assessment for your accounting or bookkeeping firm.