In short (TL;DR)
Free and regular paid ChatGPT conversations are used to train the model by default. You should not paste invoices, payroll data, or customer lists there. Business accounts (ChatGPT Business and Enterprise, Claude for Work, Gemini in Google Workspace) do not train with your data, and this is stated in the contract. However, in both cases, GDPR responsibility remains with you, because invoices and payroll contain personal data. Three rules: use a business account, do not put personal data in the free version, and agree on clear AI rules within the company.
Does ChatGPT learn from your data?
It depends on the account. The difference is not small print, but fundamental:
| Tool | Free / Standard Account | Business account |
|---|---|---|
| ChatGPT | chats are used for training by default (can be turned off) | Business and Enterprise do not train according to your data. |
| Claude | regular account chats are used for training by default (can be turned off) | Claude for Work and API do not train with your data. |
| Gemini | regular app activity can be used for training | Workspace data is not used for training (contractual promise) |
OpenAI confirms business account principles in its on the company privacy page and the Google Workspace promise is part of the data processing agreement, as explained by C# Corner Review. One more nuance: the content of business accounts may also be retained for a short period of time to detect misuse, for example, for about 30 days at OpenAI. „Not trained” does not mean „deleted immediately.”.
Why is accounting data particularly sensitive?
Because they are full of personal data. A sales invoice has the customer's name and contact information, a purchase invoice has the supplier's representative's details, a payroll file has names, personal identification numbers and bank accounts. In terms of GDPR, you are the controller regardless of which tool the data is transferred to. Metomicu 2026 Overview puts it well: the real risk starts before the prompt: with the decision of what data makes it into the chat window in the first place.
Simple test: if you wouldn't send this data to a stranger by email, don't paste it into a free AI chat.
What does GDPR require of you?
- Data Processing Agreement (DPA): If an AI tool processes personal data, there must be a contract with the service provider. This is standard on business accounts, not on free accounts.
- Minimize: Give the AI as little data as the task requires. The customer ID is not required for the accounting recommendation.
- Transparency: If AI tools are part of your workflow, reflect this in your privacy notice.
- Right to erasure: You need to be able to answer where customer data is located even if it went through an AI tool.
Practical rules for accountants
- Only use a business account for work purposes - the difference with a free account is contractual, not cosmetic.
- Don't put personal information or bank details in a general-purpose AI chat, not even "for once.".
- Remove or replace names and numbers when asking AI for advice based on a sample.
- Agree on a written AI policy within the company: what is allowed, what is not allowed, with which account.
- Prefer workflows where data stays within the accounting system and AI comes to the data, not the other way around. We will write more about this in the article AI accounting.
If you want an AI assistant to see your accounting in a controlled way, without pasting data into a chat window, then MCP interfaces are designed for this - we explain them in the article MCP and Accounting AI Assistant.
Summary
You may provide accounting data to ChatGPT if you use a business account that has a data processing agreement and does not train with your data. The free version is the source of training data and you may not put personal data there. In any case, the responsibility for GDPR is yours: minimize, anonymize and write down AI rules. This article is a general overview, not legal advice.
Try Bilnex's free invoice processing, where the data stays within the system.
FAQ
Does the free ChatGPT use my data for training?
Yes, free and regular paid account chats are used to train the model by default, although this can be turned off in settings. Business accounts (ChatGPT Business and Enterprise) do not train with your data.
Which AI account is right for enterprise data?
Business account with a data processing agreement and a promise not to train on the data: ChatGPT Business or Enterprise, Claude for Work, or Gemini as part of Google Workspace. Free accounts are not suitable for business use.
Can anonymized data be put into AI for free?
Caution. If names and numbers are replaced so that the person cannot be identified, the risk is lower, but semi-hidden data (such as initials or a rare job title) remains personal data under GDPR. It is safer to use a business account.
Does a business account mean that the data is deleted immediately?
No. Business accounts do not use data for training, but content may be retained for a short period of time to detect misuse, such as approximately 30 days for OpenAI. Check with your service provider or your contract for exact retention periods.