Data access after Project Online (PWA) retirement

Hi Pablito,

That's a great and very practical question, and unfortunately the answer is not what most people want to hear.

Based on the information I have gathered from multiple direct interactions with Microsoft (support cases, partner community meetings, and official replies on Microsoft Learn), the entire PWA site collection will become unavailable after September 30, 2026. This means that any content hosted on that site collection, whether it is related to Project Online or not, will no longer be accessible.

So to answer your question directly: yes, your custom lists created on the PWA site will also become unavailable, even though they are not related to PWA functionality and are used for other business processes.

The key point here is that Microsoft is decommissioning the PWA site collection as a whole. It does not matter whether the content on that site is project data, a custom list, a document library, or anything else. If it lives on the PWA site (or on a subsite created under the PWA site collection), it will be gone after retirement.

What you should do before September 30, 2026:

1. Identify all custom lists and non-PWA content stored on your PWA site collection.
2. Migrate those lists to a separate, standalone SharePoint site that is not tied to the PWA instance. You can use SharePoint native tools, Power Automate flows, or third-party migration tools to move the data.
3. Update any links, integrations, or automations that reference those lists to point to the new location.
4. Do not wait until the last moment. The retirement is a hard stop with no grace period and no read-only window guaranteed by Microsoft.

I've asked Microsoft this same question multiple times through different channels, and the answer has been consistent: everything under the PWA site collection goes away. Plan accordingly.

Hope this helps! If you have follow-up questions, feel free to reply here.

Hi Shardul,

Great question, and this is actually one of the most important distinctions in this entire retirement topic.

Based on the information I’ve gathered from Microsoft (including official replies and partner-level discussions), the impact depends primarily on where the SharePoint site is hosted, not just how it was created.

In your scenario:

• Your PWA site collection → will become unavailable after retirement
• Your project sites created as subsites under a separate (non-PWA) site collection → this is a different case

If your project sites are truly hosted under a separate SharePoint site collection (not tied to the PWA site collection), then there is a strong indication that they are not directly impacted by the PWA retirement itself.

However, there is an important nuance:

Factual (confirmed based on Microsoft guidance):

• SharePoint sites that are linked to Project Online and part of the PWA site collection will become unavailable after retirement

Hypothesis (to validate in your environment):

• If your project sites are:
• Hosted under a completely independent SharePoint site collection
• Not structurally dependent on the PWA site collection
  Then they may continue to exist after retirement

Risk to consider (very important):
Even if the site physically remains available:

• Any integration with Project Online (links, workflows, provisioning logic, metadata sync, navigation) will break
• Some project-specific features may stop working or become orphaned
• There is no explicit official Microsoft statement confirming long-term support for this hybrid scenario

So while the site itself may survive, its functional context as a “project site” may not.

Recommendation:

To reduce risk, I strongly suggest you:

1. Validate if those sites are truly independent at the site collection level
2. Identify any dependency on Project Online services (metadata, navigation, workflows, automation)
3. Plan to treat them as standalone SharePoint sites going forward
4. If they are business-critical, consider validating this behavior with Microsoft support for your tenant

In short:

• PWA site collection → definitely goes away
• External SharePoint site collections → likely remain, but with functional limitations and no guarantees

Hope this helps clarify your scenario.

Hi humphriesk,

I completely understand your reasoning, and honestly, your approach is technically sound from a SharePoint perspective. Under normal circumstances, if you detach a subsite from its business logic and rely only on SharePoint permissions, it should continue to exist independently.

However, based on everything I have confirmed directly with Microsoft (including multiple support cases, partner discussions, and official responses), the behavior here is not driven by permissions mode or logical dependencies. It is driven by the decommissioning of the PWA site collection itself.

This is the key point: once Project Online is retired, the entire PWA-backed site collection becomes inaccessible, not just the Project data layer.

Because of that:

• It does not matter if you use PWA permissions mode or SharePoint permissions mode
• It does not matter if the project is deleted from Project Center
• It does not matter if the subsite is read-only or “archived”

If the site (or subsite) is hosted under a PWA site collection, it is expected to become unavailable after retirement.

Most guidance, including official responses, consistently points to a hard cutoff where both Project data and associated SharePoint content become inaccessible after September 30, 2026.

So unfortunately, the “small faint hope” scenario, where detached SharePoint subsites continue to exist independently, does not align with what Microsoft has been communicating so far.

Practical recommendation:

If those archived sites are important, the safest path is:

1. Migrate those SharePoint subsites to a separate, standard SharePoint site collection (outside PWA)
2. Treat them as independent content repositories going forward
3. Do not rely on permission mode or project deletion as a preservation strategy

I agree this significantly increases the migration effort, especially for archived content, but at this point it’s the only approach that aligns with the current Microsoft guidance.

Hope this helps clarify the situation.

Thanks, Dale, 

We’re aligning our plans to the same assumption: once Microsoft “pulls the plug,” PWA data will be gone. That said, it would be extremely helpful if Microsoft could offer a **read-only retention window** (even limited) after retirement, for example, continued read access to PWA data and linked SharePoint project sites, or at least to the OData or CSOM export endpoints.

A short, time-boxed grace period (6–12 months) would let customers validate migrations, access historical records for audits, and avoid migrating large volumes of history they only need for reference. Given the tight timeline, this would significantly reduce risk and effort across tenants.

If you see any movement or formal statement from Microsoft on a read-only or historical access window, please share.

Thanks, Rod, same view here.

Until Microsoft publishes official guidance on data retention, we’re planning under the assumption that PWA data and the associated SharePoint project sites won’t be accessible after retirement. If you see any official statement on post-retirement access/retention, please share it.

Thanks, John,
I watched the thread you pointed to (great overview).
We also published a video covering the retirement topic (for context: https://youtu.be/R4gtv-RgR9g - the video is in Portuguese, but it can be auto-captioned in English).
My question here is narrower and more practical: what exactly happens to the data after the Project Online (PWA) retirement date?

• Will the data currently in Project Online remain accessible (even read-only) after retirement, and for how long?
  
  
• Will tenants still be able to view/export/migrate their data after the date? If yes, what’s the time window and supported mechanisms (e.g., OData/reporting DB, CSOM/REST, etc.)?
  
  
• Regarding the SharePoint project sites linked to PWA, will they remain available (and editable) as standard SharePoint sites? For how long and under what constraints?
  
  
• Is there an official Microsoft guidance or policy page that states data accessibility/retention timelines to help customers plan migration and compliance?
  
  If you (or someone from Microsoft) can share the official documentation or a definitive statement on post-retirement data access and retention, that would be extremely helpful for customers planning migrations and audits. Thanks in advance!