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ChatGPT Projects or custom GPTs: what should your company implement?
Short answer
Choose a ChatGPT project for a case that develops: a quote for one client with further agreements. Choose a custom GPT to share the company's way of doing a task with a whole department. Keeping these needs apart makes documents easier to maintain and limits mixing of client data. Neither one needs an app built on the API.
- net per day of closed training for the team
- from €1,150
- people in one training group
- up to 15
- after this time, we measure the effect on the same tasks
- 30 days
We belong to the OpenAI and Anthropic partner programmes and learn through their official courses. What this means ↓
Author: Syntalith · 3 min read
Statistics
ChatGPT in companies: statistics 2026
2 tools
for two different needs: a project runs a case, a custom GPT repeats the company's way of working. Both are in the ChatGPT Business plan.
15.1%
According to Eurostat (2025), 15.1% of people aged 16 to 74 in the EU used generative AI tools for work.
49%
According to the European Commission (2026), 49% of EU SMEs and mid-caps name legal uncertainty as a barrier to AI.
Source: European Commission, Flash Eurobarometer 578 (2026) ↗
40%
According to a study published in Science (2023), ChatGPT cut the time 453 professionals spent on writing tasks by 40%.
Source: Noy and Zhang, Science (2023) ↗
32.7%
According to Eurostat (2025), 32.7% of people aged 16 to 74 in the EU used generative AI tools in the previous 3 months.
Figures checked: 22 October 2026
What separates a project from a custom GPT
| Question | ChatGPT project | Custom GPT |
|---|---|---|
| What you organise | Work around a case: conversations, files, instructions | How an assistant behaves for a set task |
| Example | One quote with further agreements | Writing quotes by the department's rules |
| Where the context comes from | The project's materials and conversations | The GPT's configuration and the current conversation |
| What you update | The case's materials and agreements | Shared instructions, knowledge and features |
| Who maintains it | The person running the case | The owner of the company's way of working |
OpenAI describes projects as spaces that gather conversations, files and instructions, and a custom GPT as an assistant configured for a specific use. According to the documentation of 30 September 2026, you cannot create new GPTs on the personal Free, Go, Plus and Pro accounts. In Business, Enterprise and Edu workspaces the permissions decide.
Where Space fits into this choice
According to OpenAI's guide of 1 October 2026, Space replaces Library, and projects stay. Pages add shared editing of documents. So you may need a project to run a case and a page to work on its document. The details are in the article on Space and Pages.
An example: one quote and a shared department standard
Project "Quote for client X"
one case
The brief, confirmed agreements and working drafts. The person running it keeps track of which version applies.
GPT "Quote scope"
the whole department
Service descriptions and working rules, shared by everyone. No data of individual clients.
The client's details stay in their project, and the GPT gets only material suitable for every authorised user. The creator of a GPT does not see its users' individual conversations, but the GPT's shared knowledge is visible to everyone who uses it.
Access before you add documents
A shared project gives its members access to the project's whole context. An instruction such as "do not show client A's data" does not replace the sharing settings.
- One project per case, or a team with the same scope of permissions
- A test on an account that should have access and on one that should not
- A check of who can join through an invitation link
- A list of people who may change the GPT's configuration
- A decision whether the GPT connects to apps and API actions, because data may then go to an outside service
Updating on a small set of cases
- 01SetA complete brief, a missing deadline, conflicting requirements and an old price list.
- 02TrialWhether the tool points out the gap or tries to fill it.
- 03SwapA new price list, the old copy deleted, the same trial in a new conversation.
- 04RepeatThe process owner repeats the test after every change of materials.
Do not assume the copies sync with the source file automatically. If nobody answers for keeping it current, a good first version will start giving outdated information over time.
The most common mistakes
The first mistake is one big "Clients" project where every client's documents land. Every member then sees the whole context. The second is a GPT loaded with specific clients' quotes as "examples": their data reaches every user in the department. The third is no owner, so the price list in the GPT is two quarters old.
What ChatGPT projects and GPTs cost and when they pay back
- Time saved
- 4 people × 1 h a week × 4.33 = 17.3 h
- Value of that time
- €604
- Licences
- $100 (€89)
- Left after licences
- €515 a month
Payback of a €1,150 rollout
2.2 months
The hours saved are the scenario's assumption, which we check by timing the tasks before the training and after 30 days. €34.90 an hour is the EU average hourly labour cost for 2025 according to Eurostat. Licences with monthly billing, converted at the ECB rate of 1.1205 USD per euro on 22 October 2026.
Add about 10 hours to the budget for sorting the materials, the instructions and the tests, about €349. If the result should land in the CRM on its own or run on a schedule with monitoring, you need an integration through the API, from €3,000 net. Choosing the project, the GPT and the team's rules is covered by the ChatGPT rollout for your team.
Worked example · Scenario
How we count the payback: a team in ChatGPT
We run the same count for your team's tasks in the free analysis.
€4,534
a month for finding agreements and handing over cases in a team of 10
Payback: 1 mo.
3 hours a week per person for finding agreements and handing over cases is our assumption. A 30% cut sits within the range of controlled studies (MIT: 40%, Harvard and BCG: 25%). €34.90 an hour is the EU average hourly labour cost for 2025 according to Eurostat, for companies with 10 or more employees. Licence: ChatGPT Business or Claude Team at 20 USD per person a month on annual billing, about €17.85 at the ECB rate of 1.1205 USD per euro on 22 October 2026. Rollout: from €1,150 for up to 10 people, from €2,300 for 11 to 40 people.
See the full calculation →
