It's one of the most common questions we're asked: "We've got Microsoft 365 — should we just roll out Copilot, or do we need something custom?" It's a reasonable question, and the answer is almost always "both, but for different things." Understanding which tool belongs where will save you significant money and avoid the frustration of deploying an expensive AI product that doesn't deliver on its promise.
Let's be direct about what each option is, what it does well, and where it falls short.
Microsoft 365 Copilot is an AI assistant woven throughout the Office suite — Word, Excel, PowerPoint, Outlook, Teams. It uses your organisation's Microsoft 365 data (emails, documents, meetings) as context, and OpenAI's models under the hood, to help you draft documents, summarise meetings, generate presentations, and query your data in natural language.
At around £30 per user per month, it's a significant investment for most SMEs. The value proposition is compelling in theory: every person in your business gets an AI assistant that knows your company's context. In practice, the return on that investment depends heavily on how well your M365 environment is set up, how your team actually works, and whether the tasks Copilot is good at are the ones your business most needs to accelerate.
Copilot earns its licence fee when the work is general, varied, and tied to the Microsoft 365 ecosystem. Specific areas where it consistently delivers:
For knowledge workers doing varied desk-based work, a well-deployed Copilot can genuinely save 30–60 minutes a day. Across a team, that compounds quickly.
Copilot is a general-purpose assistant. It is not designed for, and cannot replace, a purpose-built AI tool that does one specific thing extremely well. The limitations show up in a few predictable places.
It can't integrate with systems outside Microsoft 365. If your business runs on a CRM, an ERP, a bespoke database, or any system that isn't part of the Microsoft stack, Copilot can't see it, can't read from it, and can't write to it. This is a significant constraint for most businesses, which operate across multiple platforms.
You can't control its behaviour with precision. You can't instruct Copilot to always respond in a specific format, always apply a specific set of business rules, or always follow a defined workflow. It's a conversational assistant, not a governed process engine.
The outputs aren't auditable in the way compliance requires. For regulated industries, financial services, legal work, or anywhere that an AI decision needs to be explainable and logged, Copilot's general-purpose nature makes auditability difficult.
It won't automate end-to-end processes. Copilot helps individuals work faster. It doesn't replace a workflow — it accelerates parts of one. Genuinely automating a multi-step business process (receiving an invoice, extracting data, matching to a PO, flagging exceptions, updating your finance system) requires a different architecture entirely.
Custom AI tools — built on models like Claude via API, or using Power Automate with AI Builder, or bespoke code — make sense when:
| Scenario | Copilot | Custom AI |
|---|---|---|
| Summarise this meeting recording | ✓ Copilot — native Teams integration, instant | Overkill |
| Process 200 invoices per month, extract line items, match to POs | Cannot do this end-to-end | ✓ Custom — built once, runs automatically |
| Draft a first version of a client proposal | ✓ Copilot — good for general drafting | Possible, but unnecessary |
| Answer customer queries using your specific product knowledge base | Possible via SharePoint, but inconsistent | ✓ Custom — reliable, on-brand, auditable |
| Analyse sales data and flag anomalies | Good for ad-hoc queries in Excel/Teams | ✓ Custom for scheduled automated analysis |
| Onboard new employees with guided Q&A | Partial — can surface documents | ✓ Custom — structured, consistent experience |
For most UK SMEs, the optimal AI strategy combines both. Roll out Copilot to knowledge workers who will benefit from general productivity gains — it's a strong product for that use case and the M365 integration is genuinely useful. Simultaneously, identify your two or three highest-value, most repetitive specific processes and build custom AI tools for those.
The custom tools will typically deliver a more measurable and significant ROI than Copilot, because they're solving a defined problem with a defined outcome. But Copilot will broadly raise the floor of AI capability across your team without requiring any bespoke development.
The question we ask every client: "What does your team do every week that takes significant time, follows a consistent pattern, and produces a predictable output?" Those are your custom AI opportunities. Everything else is probably Copilot territory.
We help businesses deploy M365 Copilot properly — which means assessing your current M365 hygiene, ensuring the right permissions and data classification are in place before Copilot can access sensitive content, and training your team to get the most out of it. We also design and build custom AI tools for the specific processes where Copilot isn't the right fit.
If you're weighing up whether Copilot is worth it for your business, or wondering what a custom tool for a specific process might cost and deliver, that's exactly the kind of conversation we have on a discovery call.
We'll give you a straight answer in a 60-minute conversation — no sales pitch, just a clear-eyed assessment of what makes sense for your business.
Book a Discovery Call