Copilot 365 vs Google Workspace AI: compliance comparison for enterprise buyers

TL;DR. Both products are tenant-bound enterprise AI: customer data stays in the buyer's existing Microsoft 365 or Google Workspace tenant by default, no training on customer content, BAA available on healthcare plans. The compliance picture diverges on subprocessor depth (Copilot added Anthropic as a subprocessor in January 2026 and that route is out of EU Data Boundary scope), EU Data Boundary maturity (Microsoft has the more developed published scope), and the AI Act deployer angle for HR-adjacent Copilot Agents.

How the two compare

The full read for each lives in the Microsoft 365 Copilot profile and the Google Gemini profile. The eight-clause DPA hub structure sits at DPA for AI vendors.

1. Tenant model and data residency

| | Microsoft 365 Copilot | Google Workspace Gemini | |---|---|---| | Default location of customer content | Buyer's Microsoft 365 tenant | Buyer's Google Workspace tenant | | Default retention of AI interactions | Tenant-controlled (lives in the buyer's M365 substrate) | Tenant-controlled (lives in the buyer's Workspace storage) | | Data residency commitment | EU Data Boundary scope on Enterprise plans; specific Copilot routes have carve-outs | Workspace data residency available on Enterprise Plus; Gemini-for-Workspace inherits | | Tenant-bound default applies to | Microsoft-hosted Copilot features | Google-hosted Gemini-for-Workspace features |

Both are tenant-bound by default. The buyer's compliance posture for the underlying M365 or Workspace tenant largely flows through to the AI feature; the AI feature does not relocate the data.

2. Training default on customer content

| | Microsoft 365 Copilot | Google Workspace Gemini | |---|---|---| | Use of customer content to train base models | No | No | | Use of prompts and responses to improve the AI feature | No (commercial tier) | No (commercial tier) | | Per-tenant fine-tuning available | Limited in M365 Copilot; broader in Azure OpenAI for custom builds | Available on Gemini for Workspace Enterprise; tenant-scoped | | Contract location | M365 Services Terms + DPA; Microsoft Products and Services DPA | Workspace Customer Agreement + Cloud Data Processing Addendum |

The commercial default at both is protective. The Azure OpenAI and Gemini-Enterprise fine-tuning routes are tenant-scoped, so the customer's training data does not enrich another tenant's model.

3. Subprocessor depth and the Anthropic / OpenAI question

| | Microsoft 365 Copilot | Google Workspace Gemini | |---|---|---| | Underlying model provider | OpenAI (primary); Anthropic added 2026-01-07 | Google (Gemini family) | | Foundation model providers as subprocessors | OpenAI and Anthropic both appear on the M365 Copilot subprocessor list | Google models are first-party; no external foundation-model subprocessor | | EU Data Boundary scope of the Anthropic route | Explicitly out of scope as of 2026-01-07 | N/A | | Cloud subprocessor | Microsoft Azure (first-party) | Google Cloud (first-party) |

This is the cleanest point of divergence. M365 Copilot's January 2026 subprocessor expansion brings Anthropic into the buyer's data-flow diagram, and Microsoft has been explicit that the Anthropic route is outside the EU Data Boundary commitment. Buyers who chose Copilot in part because of the EU Data Boundary need to read the carve-outs and decide whether the Anthropic-routed features are acceptable, or whether the tenant should disable those features.

Google Workspace Gemini avoids the question because the underlying models are Google's own, and the cloud is Google Cloud. Subprocessor depth is shallower, which simplifies the buyer-side documentation.

4. EU/UK transfer mechanism

| | Microsoft 365 Copilot | Google Workspace Gemini | |---|---|---| | SCC version | 2021 Module 2 | 2021 Module 2 | | UK Addendum | Yes | Yes | | EU Data Boundary commitment | Published, with named carve-outs (including the Anthropic-routed Copilot features) | EU data residency on Enterprise Plus; no equivalent "Data Boundary" branding | | Region-locked enterprise option | Microsoft Cloud for Sovereignty for higher-assurance buyers | Sovereign Workloads / Assured Workloads for higher-assurance buyers |

Microsoft has the more developed published Data Boundary; Google has the equivalent functionality with less public marketing around it. For buyers in regulated industries (financial services, healthcare, public sector), the sovereign-cloud options at both vendors are the realistic answer rather than the standard Enterprise tier.

5. HIPAA BAA

| | Microsoft 365 Copilot | Google Workspace Gemini | |---|---|---| | BAA available | Yes — Microsoft signs BAAs for in-scope M365 and Azure services; Copilot inherits where in-scope | Yes — Google Workspace BAA covers Workspace Gemini for Healthcare and Life Sciences customers on eligible plans | | Tier required | Enterprise (specific plans) | Enterprise (specific plans) | | Consumer / SMB tier eligibility | No | No |

Both sign BAAs on the enterprise tier. The procurement workflow is the same on both sides: confirm tier eligibility with the sales channel, execute the BAA before any PHI enters the system, run a fresh Security Rule risk analysis. See the HIPAA hub for the full checklist.

6. AI Act deployer obligations

Both vendors are GPAI providers under the EU AI Act. The deployer-side obligations land on the buyer regardless of which vendor they pick. The use-case classification matters more than the vendor:

• A Copilot or Workspace Gemini deployment used for general office productivity (drafting emails, summarising meetings, finding documents) sits in minimal-risk or transparency territory.
• A Copilot Agent or Workspace integration used in HR (CV screening, performance scoring, promotion decisions) brings the deployment into Annex III high-risk territory under either vendor. Deployer obligations land on the buyer.
• A Copilot Agent built on top of M365 data that performs decisions affecting access to essential services (banking, insurance, public services) is high-risk under both vendors.

The EU AI Act hub covers the deployer assessment in full.

7. The Copilot Agents and Workspace integration angle

Copilot Studio and Google Workspace's AppSheet / Gemini-for-Workspace integration layer both let the buyer build custom agents on top of tenant data. This is where the AI Act exposure can climb fast:

• The agent's use case determines the AI Act risk tier, not the underlying platform.
• The custom data sources the agent connects to may expand the personal-data footprint beyond what the standard tenant DPA covers.
• Logging and human oversight controls become design-time buyer decisions, not vendor-default settings.

Buyers building agents on either platform should run the deployer assessment on the agent, not on Copilot or Gemini in general.

Picking between them

Pick Copilot when:

• The buyer is already on Microsoft 365 and the procurement gate values the published EU Data Boundary documentation
• The buyer needs the broader Microsoft Purview, Sensitivity Labels, and Conditional Access integration for DLP-driven controls on the AI surface
• The use case is HR-adjacent and the buyer wants Microsoft's Responsible AI Standard documentation as part of the deployer evidence base

Pick Workspace Gemini when:

• The buyer is already on Google Workspace and a fully first-party model stack is preferable (no Anthropic-style subprocessor question)
• The buyer prefers the shallower subprocessor depth for simpler Transfer Impact Assessment documentation
• The buyer's developer workflows use Google Cloud / Vertex AI as the production AI surface and Workspace Gemini is the office-productivity layer above

Consider Cloud for Sovereignty or Assured Workloads when:

• The buyer sits in financial services, public sector, or healthcare with sovereign-cloud requirements
• The standard EU Data Boundary or Workspace data residency is not enough on its own to clear the procurement gate

The agents question changes the answer

If the buyer's actual deployment plan is "build Copilot Agents" or "build Workspace integrations" rather than "use the off-the-shelf AI feature," the vendor selection question is downstream of the AI Act deployer assessment for the agent itself. Run that assessment first.

Related reading

• The eight DPA clauses both vendors are scored against: DPA for AI vendors
• The deployer-side AI Act read: EU AI Act for AI buyers
• The healthcare-specific procurement checklist: HIPAA for AI tools
• Cross-comparison: OpenAI vs Copilot enterprise compliance
• Cross-comparison: Gemini vs Vertex AI compliance

For ongoing AI compliance support, work with Janus DPO-as-a-Service. Browse the vendor index or other vendor comparisons.