How to Train an AI on Your Own Business Knowledge (Custom GPTs, Claude Projects)

Custom GPTs and Claude Projects let you build an AI assistant that actually knows your business: your products, pricing, processes, tone of voice, common customer questions, and anything else you feed it. Once trained, anyone on your team can use it to get accurate, on-brand answers in seconds.

This guide shows you how to set one up, what to put in it, and how to get the most out of it for a small Australian business.

Why this matters

Generic AI tools are useful but generic. When you ask ChatGPT to “write a quote email for my plumbing business,” it doesn’t know your rates, your service area, your name, or your tone. Every response needs heavy editing.

A trained custom assistant knows all of that. You ask for a quote email and get something that sounds like you wrote it, with your actual details.

Option 1: Custom GPTs (ChatGPT Plus, AU$30/month)

What it is

ChatGPT Plus subscribers can create “Custom GPTs”: personalised versions of ChatGPT with a custom system prompt, uploaded knowledge documents, and specific capabilities turned on or off.

How to build one

1. In ChatGPT, click your profile icon → My GPTs → Create a GPT
2. Use the GPT Builder to describe what you want in plain language (it’ll configure the settings for you)
3. Or click Configure to set up manually

The Configure tab: what to fill in

• Name: “[Your Business] Assistant” or “Marketing Helper” or whatever fits
• Description: Brief summary of what it does
• Instructions: This is the core: detailed guidance on who the assistant is and how it should behave (see template below)
• Knowledge: Upload files: your product/service list, pricing, FAQs, tone of voice guide, policy documents
• Capabilities: Enable web browsing, image generation, or code if needed

Instructions template for a business GPT

You are the AI assistant for [Business Name], a [type of business] based in [suburb/city], Australia.

About the business:
[paste 3-5 sentences about what you do, who you serve, your key differentiators]

Tone of voice:
[e.g. "Friendly, professional, and direct. We're a local business: not a corporate. Use plain Australian English. Don't be formal. Don't use American spellings."]

What you help with:
[list the main tasks: e.g. writing customer emails, drafting quotes, answering FAQs, creating social posts, writing product descriptions]

What you don't do:
[e.g. "Don't give legal or financial advice. Don't make up pricing: refer to the uploaded pricing document. If you don't know something, say so and suggest they contact us directly."]

Our pricing: [or "See uploaded pricing document"]
Our service area: [areas you cover]
Our contact details: [phone, email, website]

When writing on behalf of the business, always sign off from [your name/business name].

Option 2: Claude Projects (Claude.ai, free tier available)

What it is

Claude Projects is Anthropic’s version of the same concept: a persistent “project” with custom instructions and uploaded documents that persist across all conversations within that project.

How to set it up

1. Go to claude.ai and sign in
2. Click Projects in the left sidebar → Create Project
3. Name your project (e.g. “[Business Name] Knowledge Base”)
4. Click Edit Project Instructions and paste your business brief (same template as above)
5. Upload your knowledge documents using the Add Content button

Now every conversation you start within that project has access to your instructions and documents.

What to upload as knowledge documents

The documents you upload become the AI’s reference material. Good documents to include:

• Service/product list with descriptions and pricing
• FAQs: the real questions customers ask
• Tone of voice guide: words you use/avoid, example phrases, personality
• Email templates: quote emails, follow-ups, onboarding emails
• Common scenarios, “When a customer complains about X, we respond by…”
• Staff handbook highlights: key policies, how things work
• Past marketing copy: so it learns your existing voice

Practical uses once it’s set up

• “Write a quote email for a domestic kitchen renovation, 3 days work, estimated $2,800 including materials”
• “Write a social post announcing we’re now offering weekend appointments”
• “A customer is asking about our cancellation policy: write a response”
• “Draft a follow-up email for a lead who enquired last week but hasn’t responded”
• “Write a Google review response for this complaint: [paste review]”

With your business knowledge loaded, these prompts return usable output instead of generic templates.

Sharing with your team

• Custom GPTs: Can be shared privately (link-only access) with team members who have ChatGPT accounts
• Claude Projects: Currently personal to your account, but you can export the instructions and have team members set up their own copy
• ChatGPT Team plan (~AU$37/user/month): allows shared Custom GPTs across a team with privacy controls

The bottom line

Generic AI tools are a starting point. An AI trained on your business is a genuine business tool. The setup takes a couple of hours: writing your instructions, gathering your documents, testing the outputs. After that, you have an assistant that knows your business as well as you do, available to your whole team, at any time.

Related: AI for Regional Australian Businesses: What Actually Works in 2026 | AI Tools for Australian Sole Traders: The Complete 2026 Guide

Related reading: How to Build an AI Workflow | Best AI Tools for Australian Small Business

📊 Compare AI tools side by side | 💼 Free resources & AI prompt packs

More step-by-step guides: How-To Guides for Australian Small Business — practical guides organised by the problem you’re trying to solve.