The short answer
If you already pay for one and use it most days, stay with it and set it up properly. Switching tools won't fix generic answers. Context will.
If you're starting fresh, try the same real job in both and keep the one whose draft needs fewer edits. Our setup is built around Claude and includes a ChatGPT version, so you don't have to choose before you start.
Side by side
As listed on each company's pricing page on 19 October 2026. Claude shows prices in US dollars; ChatGPT shows UK prices in pounds.
| Compared | Claude | ChatGPT |
|---|---|---|
| Made by | Anthropic | OpenAI |
| Free plan | Yes, with usage limits. No Claude Code | Yes, with usage limits |
| Paid plans for one person | Pro: $20 a month | Go: £7 a month (may include ads). Plus: £20 a month |
| Heavy use | Max: from $100 a month | Pro: from £89 a month |
| For a team | Team: from $20 a person a month, billed annually | Business: from £15 a person a month, billed annually, from two people |
| Projects (upload instructions and files once, use them in every chat) | Up to five on Free; included on paid plans | On every personal plan, Free included |
| Chats used to train models | Personal plans: you can opt out. Team and Enterprise: not by default | Personal plans: you can opt out. Business and Enterprise: not by default |
| Where to opt out | Settings, then Privacy | Settings, then Data controls, then Improve the model for everyone |
Sources, checked 19 October 2026: Claude plans and pricing, ChatGPT plans and pricing, Data controls in ChatGPT (OpenAI help).
Where they're alike
- Both write, summarise and plan in plain English.
- Both read the documents, spreadsheets and photos you give them.
- Both let you upload instructions and files to a Project, so every chat starts with your context. A Project holds copies: the tool can read them but not update them.
- Both let you keep your chats out of model training: by a setting on personal plans, and by default on their business plans.
How to choose
- Already paying for one? Use it, and give it your business context.
- Several people need it? Compare Claude Team with ChatGPT Business. Both keep your chats out of model training by default.
- Watching every pound? ChatGPT Go is the cheapest paid plan of the two, but it may show ads.
- Still not sure? Switch off model training in both, then give each the same job with nothing confidential in it, such as replying to a common customer question. Keep the one whose draft you'd send with fewer changes.
What matters more than the tool
Out of the box, both answer like they've never met you, because they haven't. What changes the answers is a short brief on your business: what you do, who you work with, how you sound and where you're going.
Our free 15-minute voice interview writes that brief for you. We turn it into your knowledge pack, with a Claude version and a ChatGPT version, and a team of seven AI advisors briefed on how you work. £200 including VAT, paid once.
AI Business Knowledge Pack is independent and not affiliated with Anthropic or OpenAI. Plans, prices and settings change, so check the official pages before you buy.