There is a difference between an AI assistant and an AI system. ChatGPT and its rivals are assistants: general-purpose tools your team chats with in a browser. They are genuinely useful, and on their business tiers they are far safer with company data than most people assume. But if you are comparing alternatives because a general assistant is not reaching far enough, the honest landscape looks different from the usual roundup. This page compares the main enterprise assistants fairly, then sets out the option they all leave out: a system you own.
We build full-code custom and private AI, so the custom tier at the end is ours, and we have written this to be accurate rather than flattering. Every claim below is as of June 2026 and should be reconfirmed on each vendor's own documentation.
Methodology and disclosure. Pricing and data-handling claims are taken from each vendor's public documentation and pricing pages as of June 2026, with material claims hedged where the public source is third-party. Ayoob AI builds custom and private AI, so the custom tier below is ours. Every product's genuine strengths are represented fairly, and on the central question of training, all four major business tiers make a no-training-by-default commitment.
The comparison at a glance
| Private / custom (Ayoob AI) | ChatGPT (OpenAI) | Claude (Anthropic) | Gemini (Google) | Microsoft 365 Copilot | Perplexity | |
|---|---|---|---|---|---|---|
| Best for | Regulated, integrated, owned | General productivity | Long-context, safety | Google Workspace shops | Microsoft 365 shops | Enterprise search |
| Trains on your data (business tier) | No (private) | No (by default) | No (by default) | No (by default) | No (by default) | No (by default) |
| Deep system integration | Bespoke, full | Connectors / API | Connectors / API | Workspace + API | Microsoft 365 graph | Limited |
| Runs private / on-premise | Yes | No | No | No | No | No |
| UK data residency | Yes (your infrastructure) | At-rest, new Enterprise only | No (first-party) | Via Vertex pin, not the assistant | Azure UK regions | Limited |
| HIPAA BAA | Yes (private) | Enterprise / API only | Qualifying Enterprise | Covered Workspace / Vertex | Via Microsoft | Verify |
| Bespoke logic | Yes | No (general) | No (general) | No (general) | No (general) | No |
| You own the system | Yes (you own the code) | No | No | No | No | No |
The hosted assistants, compared fairly
ChatGPT (OpenAI)
Strengths. The most widely adopted assistant, with the broadest general capability and the strongest documented enterprise privacy posture: no training on Business, Enterprise, Education, or API data by default. Its compliance set is extensive, including SOC 2 Type 2, ISO 27001:2022, ISO 42001, and FedRAMP. Pricing, per third-party trackers as of June 2026, is around 20 dollars per seat per month on Business (annual), with Enterprise quote-only.
Where it falls short for some businesses. There is no self-hosted or on-premise option. HIPAA business associate agreements are available on Enterprise, Education, and the API, but not the self-serve Business tier. UK at-rest residency exists but only on new Enterprise and Education workspaces, and at-rest does not dictate where processing happens. One caveat for regulated buyers: a 2025 US court preservation order has constrained deletion of certain logs, so verify the current scope if guaranteed deletion matters.
Claude (Anthropic)
Strengths. Strong long-context performance and a safety-first design, with a clear primary-source commitment that customer data on Claude Enterprise is not used to train its models. Compliance includes SOC 2 Type I and II, ISO 27001:2022, and ISO 42001:2023, with HIPAA-ready configurations for qualifying Enterprise. Team pricing is 20 to 25 dollars per seat as standard, with a premium tier and Enterprise on quote.
Where it falls short. The August 2025 change that lets Anthropic train on consumer data by default applies only to the Free, Pro, and Max consumer plans and explicitly excludes Claude for Work, Government, Education, and the API, so business data is not in scope. The genuine gap is residency: data is stored in the US by default and there is no first-party UK residency as of June 2026, with EU options available only through Amazon Bedrock or Google Vertex. And, like the others, there is no on-premise option.
Gemini (Google)
Strengths. Deeply integrated with Google Workspace, with no training on customer data and no human review without permission on the paid business and enterprise surfaces. Vertex AI can pin data at rest to around ten countries including the UK. Compliance is broad, including ISO 27001, ISO 42001, and FedRAMP High, with HIPAA coverage on the qualifying Workspace SKU and Vertex.
Where it falls short. The free Gemini app is a different product that can be reviewed and used to improve models, and is excluded from the enterprise commitments and any BAA, so the consumer-versus-enterprise line matters. The Gemini assistant itself has no UK-only region without add-ons, and retention is admin-configurable rather than zero by default. No on-premise option.
Microsoft 365 Copilot
Strengths. The native assistant inside Microsoft 365, working across your Outlook, Teams, and SharePoint content within the Microsoft compliance boundary, and inheriting Azure UK data regions and Microsoft's advanced data residency. It does not use your tenant data to train the foundation models. Priced per user per month, commonly reported around 30 dollars as of June 2026, on top of a qualifying Microsoft 365 licence.
Where it falls short. It is most useful only if you are already standardised on Microsoft 365, and it pulls you further into Microsoft licensing. It is a productivity assistant over your Microsoft content, not a system that integrates bespoke logic with your line-of-business applications, and there is no on-premise build.
Perplexity
Strengths. Built around enterprise search and cited answers, useful for research-heavy teams that want sourced responses across web and internal content. It commits to not training on enterprise data and holds SOC 2.
Where it falls short. It is a focused search-and-answer tool rather than a general platform or an integration layer, and its residency and HIPAA position should be verified directly for a regulated use. No on-premise option.
The option they all leave out: a system you own
Every product above is a hosted assistant. For most general productivity that is exactly right, and on the business tiers they are far more private than their reputation suggests. But three needs sit beyond what any of them offers, and they are the needs that bring businesses to us.
The first is deep integration. An assistant works in a chat window. A custom system reads from and writes to your own databases, CRM, and line-of-business applications, and runs your specific logic. That is the difference between asking an AI for help and having AI run a process.
The second is private data handling. None of the hosted assistants can be self-hosted. When your requirement is that regulated or sensitive data physically never leaves your environment, the only architecture that meets it is a private system built on open-weight models running on infrastructure you control. It is also where UK data residency becomes a property of your own infrastructure rather than a vendor's region map. We set out the full case in private AI for UK regulated businesses, and the retrieval layer that makes it useful in RAG systems explained.
The third is ownership. A subscription is a tool you rent. A custom build is a system you own outright, with no per-seat ceiling and the code in your hands. We are ISO 27001:2022 and Cyber Essentials certified, hold five pending UK patents on our compute architecture, and build private and on-premise systems for regulated firms.
This is not a claim that custom beats a hosted assistant in general. It does not. For ad-hoc productivity, a business-tier assistant is the right call, and we will say so. It is a claim that once AI becomes load-bearing infrastructure for a regulated or integrated process, an owned system is the better end state. The fuller head-to-head is in custom AI software vs ChatGPT.
How to choose
- For general productivity with the broadest capability, ChatGPT on a business or enterprise tier.
- For long-context work and a clear data commitment, Claude, accepting the current lack of first-party UK residency.
- If you run Google Workspace, Gemini. If you run Microsoft 365, Microsoft 365 Copilot.
- For enterprise search with cited answers, Perplexity.
- For deep integration, private or on-premise data handling, guaranteed UK residency, bespoke logic, or ownership, a custom or private build.
If you are not sure which side of that line you are on, that is the conversation we have on a discovery call. We will tell you straight if a hosted assistant is the better fit.
Related reading
- Custom AI Software vs ChatGPT: What Your Business Actually Needs
- Compare AI automation tools and approaches
- Private AI for UK Regulated Businesses: A 2026 Decision Framework
- What Is AI Inference? Definition, How It Works, and the Cost That Matters
- RAG Systems Explained: How Private AI Search Actually Works
