Thomson Reuters Hosted Exchange retires August 31, 2026. Thomson Reuters says all Hosted Exchange mailboxes still remaining at retirement will be permanently deleted. Virtual Office CS itself is not being discontinued, so firms can migrate email and continue using their Thomson Reuters applications in Virtual Office CS.
- Hosted Exchange users should act now. Thomson Reuters’ Managed Migration Service is no longer available; remaining firms are directed to EWS-based offboarding or a Microsoft Cloud Solution Provider.
- Microsoft 365 management shifts to the firm or its provider. This includes licensing, mailboxes, authentication, retention, mail flow, and DNS settings such as MX, SPF, DKIM, and DMARC.
- Email migration does not require an application-hosting move. UltraTax CS, Accounting CS, Practice CS, and other CS Professional Suite applications can remain in Virtual Office CS.
- Firms can also reassess their hosting environment. OneUp Networks offers private cloud hosting for Thomson Reuters and mixed accounting-software environments, starting at $49.99/user/month.
- OneUp Networks plans include free setup and migration, 24/7 support, NVMe storage, daily backups with 120-day retention, scalable resources, and support for Thomson Reuters, QuickBooks, Drake, and other accounting applications.
Thomson Reuters Hosted Exchange retires August 31, 2026, and Thomson Reuters says all mailboxes still remaining in the service will be permanently deleted. Virtual Office CS itself is not being discontinued, so CPA firms can move email to Microsoft 365 and continue using their Thomson Reuters applications in Virtual Office CS. Firms that still need Hosted Exchange data should act now because Thomson Reuters’ former Managed Migration Service is no longer available; current guidance directs firms to EWS-based offboarding or a Microsoft Cloud Solution Provider.
The immediate priority is therefore protecting email data and completing the Microsoft 365 transition. After that, firms can separately decide whether continuing to run UltraTax CS, Accounting CS, Practice CS, and other applications in Virtual Office CS still makes operational and financial sense.
What Exactly Is Ending on August 31?
Thomson Reuters is retiring Hosted Exchange, the email service historically provided to Virtual Office CS and SaaS customers. The company is not announcing the retirement of UltraTax CS, Accounting CS, Practice CS, Fixed Assets CS, or Virtual Office CS itself as part of this change.
That distinction is important because email migration and application hosting are two different projects.
| Component | Status |
|---|---|
| Hosted Exchange | Retires August 31, 2026 |
| Hosted Exchange mailboxes remaining at retirement | Permanently deleted |
| Virtual Office CS | Continues |
| SaaS | Continues |
| CS Professional Suite applications | Continue |
| Microsoft Office inside VO/SaaS | Transition to M365 Office completed |
| Microsoft 365 tenant | Firm/CSP administered |
| Outlook | Continues using the firm’s configured email environment |
Thomson Reuters also says the Virtual Office CS and SaaS transition to Microsoft 365 Office applications has already been completed. Firms therefore need a supported Microsoft 365 account to use Office applications and related integrations within the environment.
Who Manages Microsoft 365 Now?
The CPA firm or its Microsoft CSP now manages the Microsoft 365 environment. Thomson Reuters continues to host supported Office applications inside Virtual Office CS/SaaS, but the firm is responsible for its tenant, licensing, users, Exchange mailboxes, mail flow, retention, and DNS/email-authentication settings.
| Responsibility | Thomson Reuters | CPA Firm / CSP |
|---|---|---|
| Host supported Office apps in VO/SaaS | Yes | — |
| Microsoft 365 tenant and licensing | — | Yes |
| Users and sign-ins | — | Yes |
| Exchange Online mailboxes | — | Yes |
| Aliases, groups and mail-flow rules | — | Yes |
| Retention/compliance settings | — | Yes |
| MX, Autodiscover, SPF, DKIM and DMARC | — | Yes |
Supported Office licenses currently include Microsoft 365 Business Premium, E3, E5, and Apps for Enterprise. Users sign in with their own Microsoft 365 credentials and complete MFA when required.
Key point: Thomson Reuters hosts the supported Office applications; your firm or CSP manages Microsoft 365 and email.ion, or compliance requirement.
What Should Firms Still on Hosted Exchange Do Now?
A firm that still needs Hosted Exchange data should treat the remaining days as a migration project, not merely an account-setting change. Start by inventorying every mailbox your firm needs to preserve, including individual users, shared mailboxes, resource mailboxes, calendars, contacts, archived material, permissions, rules, and any public-folder information.
Then establish the destination environment and identify who will administer it. For many firms, that means Microsoft 365/Exchange Online managed by internal IT or a Microsoft CSP. Thomson Reuters’ current documentation says its managed migration service is no longer available and directs firms that still need to migrate data to use EWS or contact their Microsoft CSP.
Current Migration Options
| Method | Current Status | Main Consideration |
|---|---|---|
| EWS-based migration through a CSP/provider | Current documented route | Direct migration, but firms still need validation and cutover planning |
| PST export | Available | Manual and requires careful validation |
| Thomson Reuters-Managed Migration Service | Discontinued | Historical option only |
PST export deserves particular caution. Thomson Reuters warns that exported PST data may not capture everything, damaged items can be lost, and firms remain responsible for verifying the result.
That makes a structured migration and validation process safer than treating an exported file as proof that every mailbox object survived.
What Should You Validate After Migration?
Do not consider the transition complete merely because Outlook can send and receive a new message.
A proper post-migration check should cover:
- historical email and folder structures;
- shared and resource mailboxes;
- calendars and recurring meetings;
- contacts and tasks;
- delegated mailbox and calendar permissions;
- inbox rules;
- aliases and distribution groups;
- signatures;
- archives and PST files;
- Outlook inside Virtual Office CS;
- mobile devices;
- incoming and outgoing mail;
- MX and Autodiscover;
- SPF, DKIM, and DMARC;
- MFA and authentication;
- retention and compliance policies.
Thomson Reuters’ historical Managed Migration documentation itself distinguishes data that migrated automatically from items requiring manual attention, including signatures, some shared-mailbox configuration, distribution lists, user-specific settings, public folders, and PST files. Firms using another migration process today should verify what their specific migration tool handles rather than assuming the old Thomson Reuters process applies.
Do You Have to Leave Virtual Office CS?
No. Hosted Exchange retirement does not require your firm to move its Thomson Reuters applications away from Virtual Office CS. Thomson Reuters continues to document Virtual Office CS/SaaS as a hosted environment for licensed CS Professional Suite applications and Microsoft 365 Office access. Though there are other reasons why firms are moving away from Virtual Office CS in 2026.
If Virtual Office CS currently gives your firm acceptable performance, support, application access, security, and recovery, the simplest path may be:
Hosted Exchange → Microsoft 365 while keeping CS Professional Suite → Virtual Office CS
That is a legitimate option. But the email transition also gives firms a natural point to examine whether their broader application-hosting model still fits the practice.
After the Email Migration: Should You Reassess Your Hosting Environment?
This is where the decision becomes transactional. Hosted Exchange retirement by itself is not a reason to move UltraTax CS or the rest of the CS Professional Suite. But if your firm is already reviewing Microsoft 365, support ownership, server access, backups, application integration, or hosting costs, it may be inefficient to examine email in isolation.
A typical accounting practice can end up with:
- Thomson Reuters applications in one environment;
- QuickBooks hosted somewhere else;
- Microsoft 365 managed by another provider;
- document tools on local computers;
- separate backup arrangements;
- multiple vendors when something stops working.
For firms that want to reduce that fragmentation, OneUp Networks provides managed private-cloud environments designed to host licensed accounting and tax applications together.
What Can OneUp Networks Host?
OneUp Networks currently supports Thomson Reuters CS Professional Suite applications and mixed accounting stacks that can include applications such as UltraTax CS, Accounting CS, Practice CS, Fixed Assets CS, QuickBooks, Drake, Sage, and other supported applications.
The purpose is not to replace the firm’s software licenses. The firm continues using its licensed applications while OneUp Networks manages the hosting environment.
That can be useful when staff need several applications during the same workflow and the firm wants fewer separate hosting environments or support handoffs.
OneUp Networks Thomson Reuters Hosting Plans
OneUp Networks currently publishes four Thomson Reuters hosting tiers.
| Plan | Published Price | Designed For |
|---|---|---|
| Essential | $49.99/user/mo | 1 Thomson Reuters application |
| Advanced | $69.99/user/mo | Up to 3 Thomson Reuters applications |
| Complete Suite | $89.99/user/mo | Full Thomson Reuters suite |
| Total Practice | $109.99/user/mo | TR Suite + QuickBooks, Drake, or other supported apps |
The current plan comparison also lists:
- free setup and migration;
- 24/7 human support;
- NVMe storage;
- daily data backups;
- 120-day backup retention;
- scalable resources;
- free trial availability.
That published pricing gives a firm a concrete starting point, but the correct plan should still be sized around the actual applications, user count, storage, integrations, and tax-season concurrency.
Which Plan Fits Your Firm?
- Essential makes sense when the firm wants to host one Thomson Reuters application, such as UltraTax CS.
- Advanced is designed for firms using up to three Thomson Reuters applications.
- Complete Suite targets practices that need the broader CS Professional Suite in one environment.
- Total Practice is the most relevant option when a firm wants Thomson Reuters applications alongside QuickBooks, Drake, or another supported accounting application.
Not Sure Which Configuration Matches Your Current Setup?
A useful quote should account for your current applications, users, file sizes, storage, integrations, printers, scanners, prior-year programs, and peak-season workload.
When Moving to OneUp Networks May Make Sense
A broader hosting move deserves consideration when the firm wants to:
- consolidate Thomson Reuters and other accounting applications;
- move workloads into a managed private environment;
- reduce the number of infrastructure vendors;
- obtain published 120-day backup retention;
- simplify server management and technical support;
- scale users or resources for tax season;
- replace aging office-server infrastructure;
- or address Virtual Office CS concerns that existed before the Hosted Exchange retirement.
OneUp Networks currently publishes free setup and migration across its Thomson Reuters hosting plans and supports mixed environments that can combine the CS Professional Suite with other accounting applications.
When Staying With Virtual Office CS May Be Better
OneUp Networks will not be the right move for every firm. If Virtual Office CS currently delivers the application performance, support model, recovery capabilities, workflow, and cost your firm needs, there is no reason to create a larger infrastructure project simply because Hosted Exchange is retiring.
In that situation, complete the Hosted Exchange migration, configure Microsoft 365 correctly, verify the new mail environment, and continue using Virtual Office CS. The important point is to separate the mandatory email decision from the optional application-hosting decision.
Security Responsibilities Do Not Disappear
Whether a firm stays with Virtual Office CS or moves applications to another hosting environment, Microsoft 365 administration now requires clear ownership. MFA, administrator accounts, mailbox permissions, SPF, DKIM, DMARC, retention, audit logs, endpoint protection, backups, and incident response all need defined owners.
A hosting provider can manage significant infrastructure responsibilities, but moving data to the cloud does not automatically make a CPA firm secure or compliant. Firms should continue to evaluate their own security obligations and service-provider responsibilities.
Frequently Asked Questions
No. Thomson Reuters is retiring Hosted Exchange, not Virtual Office CS itself. Firms can migrate email and continue using their licensed CS Professional Suite applications in Virtual Office CS.
Thomson Reuters says all Hosted Exchange mailboxes still remaining when the service retires will be permanently deleted. Firms that need historical data should complete migration before the deadline.
No. Thomson Reuters says its Managed Migration Service is no longer available. Current guidance directs firms that still need migration toward EWS-based offboarding or their Microsoft CSP.
No. Email and application hosting are separate decisions. A firm can migrate email to Microsoft 365 and remain on Virtual Office CS.
Yes. OneUp Networks currently offers hosting plans for individual Thomson Reuters applications, several applications, the full suite, and mixed environments containing Thomson Reuters plus QuickBooks, Drake, or other supported applications.
Published plans currently begin at $49.99 per user per month, with higher tiers at $69.99, $89.99, and $109.99 depending on the number and type of applications hosted.
Final Decision: Solve Email First, Then Decide on Hosting
For firms still using Hosted Exchange, the immediate priority is clear: protect the mailbox data you need and complete the migration before August 31, 2026. Thomson Reuters’ managed migration option has ended, and remaining Hosted Exchange mailboxes are scheduled for permanent deletion.
After the email project is under control, decide whether the broader application environment still makes sense. If Virtual Office CS continues to meet your firm’s needs, keep it.
If the transition has exposed fragmented hosting, too many support relationships, application-integration challenges, recovery concerns, or a desire for a private managed environment, OneUp Networks provides another path for hosting licensed Thomson Reuters and accounting applications.
OneUp Networks currently publishes Thomson Reuters plans beginning at $49.99/user/month, with free migration, 24/7 support, daily backups, 120-day retention, NVMe storage, and configurations that can include QuickBooks, Drake, and other supported applications.
Ready to Rethink Your Thomson Reuters Hosting?
Hosted Exchange retirement may be the right time to review more than email. OneUp Networks can host your licensed UltraTax CS, Accounting CS, Practice CS, QuickBooks, Drake, and other supported accounting applications in a managed private cloud with free migration, 120-day backup retention, NVMe storage, and 24/7 support. Compare your current Virtual Office CS setup against a configuration built around your users, applications, storage, and tax-season workload.
- Book a Demo – see how your Thomson Reuters and accounting applications can run together in a managed cloud environment.
- Start a 15-Day Free Trial – test application access and workflow before deciding whether to migrate. No credit card is required.
- Talk to a Hosting Expert – discuss your current Virtual Office CS setup, Thomson Reuters applications, users, storage, integrations, and tax-season workload with a OneUp Networks specialist.
Disclosure
OneUp Networks is an independent cloud hosting provider and is not affiliated with, endorsed by, or sponsored by Thomson Reuters. Thomson Reuters, Virtual Office CS, UltraTax CS, Accounting CS, Practice CS, and other referenced product names are trademarks of their respective owners. This article summarizes publicly available information for general informational purposes. Firms should verify current migration, licensing, security, and service requirements directly with Thomson Reuters, Microsoft, and their technology providers.
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