The 30-Day Project Online Shutdown Checklist

The 30 days before the Project Online shutdown on September 30, 2026 will be the most operationally stressful period your PMO has faced in years. Not because of anything unexpected, but because of everything that gets deferred until it is not deferrable anymore. Open timesheets, Power BI reports that someone set up three years ago, Power Automate flows nobody remembers building, Project Plan 5 licenses on autopay since 2019. All of it surfaces in the final month.

This checklist is the plan for those 30 days. Run it now so that the last weeks of September are calm instead of chaotic.

The diagram below shows the four shutdown phases across the final 30 days before the Project Online shutdown date.

Why the Final 30 Days Go Wrong for Most PMOs

Most PMOs treat the retirement date as the export deadline. It is not. OData is throttled at roughly 100 requests per minute. A tenant with 150 projects, each with hundreds of tasks and resource assignments, can take 8 to 12 hours to fully snapshot through OData. When that same snapshot runs in the last two weeks of September alongside every other organization doing the same thing, service degradation is predictable.

The practical export deadline is September 1, 2026. That is the date by which your complete OData snapshot, .mpp exports, and timesheet history extracts should be confirmed and stored. The final 30 days before September 30 are for cleanup, communication, and license management, not for last-minute data pulls.

Two other patterns cause late-stage chaos. First, unknown consumers: Power BI reports, Power Automate flows, and Teams apps hitting the OData endpoint that nobody thought to audit until they start failing. Second, deferred timesheet work: open timesheet periods that project managers kept putting off, which suddenly become urgent when the service is about to shut down.

For context on exactly what breaks on shutdown day, see the post-retirement service sequence for Project Online. That post covers the technical shutdown sequence in detail.

Days 30 to 21: Run Your Final Tenant Inventory

This phase is about knowing exactly what you have before you try to move it. Surprises at export time are expensive; surprises at shutdown time are worse.

1. Pull a complete project inventory from OData. Use the Projects entity to list every project, its status (active, inactive, template), last modified date, and project manager. This is your export manifest. Flag projects with no updates in the past 18 months as archive candidates.
2. List all Enterprise Custom Fields. Export the custom field definitions (name, field type, formula, lookup table) from the PWA Server Settings. These definitions need to be recreated or mapped in your destination platform.
3. Inventory Enterprise Resource Pool members. Export the full resource list with skill types, calendar assignments, cost rates, and department assignments. The ERP is often the most complex piece to migrate and the most frequently overlooked.
4. Audit OData consumers. Search your Power BI tenant, SharePoint sites, and Power Automate flows for any connection using /_api/ProjectData. Catalog every report and flow; these all need remediation before September 30.
5. List all open timesheet periods. A PWA admin can view open and in-flight timesheet periods from the Timesheet Period settings page. Get a count and notify project managers to close out any periods they intend to finalize.

Run the free Project Online Inventory Checklist to walk through this audit systematically. It generates a structured export plan that your migration team can hand off directly.

Days 20 to 11: Complete All Data Exports

With a confirmed inventory in hand, this phase executes the actual data extractions. Do them in this order, from highest to lowest data-loss risk.

1. OData full snapshot. Pull the complete OData entity set: Projects, Tasks, Assignments, Resources, Timesheets, CustomFields, Baselines. Store the output in a durable location (Azure Blob Storage, SharePoint document library, or on-premises NAS). Date-stamp the export folder.
2. .mpp file export for every active project. From PWA, use File > Save As to download each project as an .mpp file. For tenants with more than 30 projects, write a PowerShell script using the CSOM API to automate the downloads. Verify that each .mpp opens correctly in Microsoft Project Desktop before moving on.
3. Timesheet history extract. Export completed and approved timesheet data to CSV or Parquet. Your finance and HR teams may need this for multi-year audit trails. Define a retention period before extracting: most compliance frameworks require 5 to 7 years.
4. Report definitions export. Download all Project Online report definitions from the Report Library in PWA. These define the structure of your existing reporting; they are reference artifacts even if you rebuild the reports on a new platform.
5. Custom field lookup tables. Export lookup table values for every custom field. These are separate from the field definitions and often get missed.
6. Baseline data per project. PWA stores up to 11 baselines per project. If your PMO uses baseline comparisons for variance reporting, verify that your .mpp exports contain all baseline sets, not just the active one.

Confirm each export is readable in isolation before treating it as complete. A 0-byte OData file or a corrupt .mpp is not a backup.

Days 10 to 4: Communicate and Close Out Dependencies

With exports confirmed, this phase winds down the live service gracefully.

1. Notify all project managers. Send a formal communication listing the shutdown date, the status of their project exports, and any open timesheets they need to close. Give them a named point of contact for questions. Do this no later than day 10 so there is time to respond.
2. Close or lock all open timesheet periods. Lock every timesheet period that will not be finalized before September 30. This prevents partially approved timesheets from creating compliance gaps in the historical record.
3. Redirect Power BI reports. For every OData-connected report you cataloged in Phase 1, update the data source connection to either a static export or a connection to your destination platform's API. Test each report after the redirect.
4. Deactivate Power Automate flows. Turn off every flow that connects to the Project Online connector or the OData endpoint. Flows that fail silently after shutdown create harder-to-diagnose problems than flows that are cleanly deactivated.
5. Remove Teams integrations. If any Teams tabs or apps surface PWA data, remove or replace them. Users will see blank or error states after shutdown if these are left in place.
6. Notify downstream report consumers. If other teams (finance, portfolio governance, executive dashboards) consume Project Online data, brief them on the shutdown timeline and confirm they have a replacement data source plan.

The Final 72 Hours

The last three days before September 30, 2026 are for confirmation, not action. If you have followed the phases above, there should be nothing urgent left to do.

1. Verify all exports are retrievable. Open a sample .mpp file in Project Desktop. Run a query against your OData snapshot. Confirm that the timesheet CSV is readable. Spot-check at least 5 percent of exported files.
2. Confirm active platform is ready. Your destination platform should already have completed a test migration of at least 5 to 10 representative projects. The final 72 hours is not the time to start a migration; it is the time to confirm that the one in progress is on track.
3. Send a final shutdown notification to stakeholders. One clean email: what stops working September 30, what continues (SharePoint project sites), and who to contact with questions. Keep it factual and brief.
4. Confirm the person on call for September 30. Someone should be monitoring the tenant on the shutdown date, able to verify the retirement sequence and respond to stakeholder questions. This does not need to be an all-hands event; one designated PMO contact is sufficient.

Project Online License Cancellation and M365 Cleanup

Project Online licenses do not auto-cancel when the service retires. If you have Project Plan 3 or Project Plan 5 subscriptions on autopay, they will continue billing until you cancel them manually.

To cancel in the Microsoft 365 admin center:

1. Go to Billing > Your Products.
2. Select your Project Plan 3 or Project Plan 5 subscription.
3. Choose Cancel subscription.
4. Confirm the cancellation effective date. Choose the end of the current billing period to avoid partial-month charges.

Do this within 30 days of shutdown to limit the exposure to one billing cycle. Review all related subscriptions at the same time: Project Online Desktop Client licenses, any additional PWA provisioning SKUs, and any Power BI Premium capacity that was dedicated to Project Online reporting.

After licenses are cancelled, check the M365 admin center for any remaining orphaned PWA site collections. Microsoft will likely clean these up as part of the retirement process, but confirm your IT team's records match the expected state.

For organizations that want a full picture of the license cost implications before and after migration, the Migration Cost Calculator provides a structured cost comparison including current Project Online spend versus destination platform licensing.

After the Project Online Shutdown: What to Expect

The retirement date is a hard cutover, not a gradual wind-down. On September 30, 2026, PWA stops serving pages and the OData API returns 410 Gone. There may be an informal read-only window of approximately 90 days after retirement, based on Microsoft's historical behavior with other SaaS retirements, but Microsoft has not guaranteed this for Project Online.

Plan your migration on the assumption that September 30, 2026 is the final day of any data access. If an informal read-only window materializes, treat it as a bonus, not a deadline.

After shutdown, keep your exported data in durable storage for at least the length of your compliance retention requirement. For most regulated industries, that means a minimum of five to seven years. Name the archive clearly with the export date and tenant name so that a future audit can identify the source without ambiguity.

The post-retirement service sequence guide covers the full technical shutdown timeline, including which services break first and what the M365 admin sees when the retirement occurs.

Run the free Project Online Inventory Checklist Walk through your tenant in about 10 minutes and get a structured export plan you can hand to your migration team. No signup required. → Open the checklist

Microsoft Project Online™ is a trademark of Microsoft Corporation. Onplana is not affiliated with Microsoft.