Is it safe to paste bank statements into ChatGPT? What to take out first

A raw bank statement should not go into ChatGPT as it is. Take out the sort code, account number, names and payee details first, and use a business plan with a data processing agreement. Do that and you can still paste bank statements into ChatGPT to sort transactions. The categorising still works. The personal data stays out.

Why bank statements are different

A bank statement looks like numbers. It is mostly people.

The account holder is named at the top. The sort code and account number sit beside it. Then every line names someone else. A landlord. A nursery. A friend repaid for dinner. A charity. A doctor.

Those payees never agreed to anything. They are third parties. Their names, and what was paid to them, are personal data under UK GDPR. Some lines can reveal health, religion or politics too.

So one statement can hold data on dozens of people. Only one of them is your client.

The details that matter most

• Sort code and account number. Together they identify an account. Paired with a name, they are useful to a fraudster.
• Account holder name and address. Ties everything to a real person.
• Payee and payer names. Third-party personal data on every line.
• Payment references. Often hold invoice numbers, policy numbers or member IDs.
• Card numbers. Sometimes shown in part on card statements.

Who is responsible

Your firm is. The Firm puts it plainly: under UK GDPR your firm is the data controller for client personal data, so pasting it into a consumer chatbot without a lawful basis, proper contracts and security assurances is a compliance failure, not a grey area.

The ICO has views on this too. According to aicura.app, UK GDPR requires a data protection impact assessment where processing is likely to result in a high risk to individuals, and the ICO's guidance says that in the vast majority of cases the use of AI involving personal data will trigger that requirement. That assessment is a written check of the risks. For more on the rules, see our plain-English guide to UK GDPR and AI tools.

Consumer and business plans are not the same

Which account staff use changes the picture a lot.

Per Witness AI, paid commercial ChatGPT tiers, including ChatGPT Business, Enterprise, Edu, and Healthcare, include controls that reduce several enterprise data-handling risks, including excluding prompts from model training by default, while consumer accounts share them for training until someone turns the setting off.

Contracts differ too. DataNorth AI notes a data processing agreement is available for ChatGPT Business, ChatGPT Enterprise and the API platform. On a consumer plan, prompts and responses may be stored, reviewed by authorised OpenAI personnel or contractors, and used to improve models unless you opt out.

Deleting a chat is not the end of it

OpenAI says deleted ChatGPT conversations and Temporary Chats are automatically deleted from its systems within 30 days. Memory is separate. Jazz Security explains that deleting a chat does not delete a memory ChatGPT built from it, and OpenAI may keep logs of deleted memories for up to 30 days.

A safe workflow for categorising transactions

The AI only needs three things to categorise: date, amount and a short description. Everything else can go.

1. Export, do not screenshot. Download the statement as CSV from the bank or your bookkeeping software. Columns are easier to strip.
2. Delete the header. Remove the account holder name, address, sort code and account number.
3. Drop the reference column. It rarely helps categorising. It often holds personal details.
4. Swap personal payees for labels. "J Patel" becomes "Person 1". Leave businesses such as "Tesco" or "British Gas". They help the AI and are not people.
5. Keep a key offline. A note of who "Person 1" is stays in your files, not in the chat.
6. Paste into the approved business account only. Ask for categories, not advice on the person.
7. Check the result. Map labels back to names in your own spreadsheet.

Take Ashcombe, a small practice. Priya exports a client's March statement. She deletes the header and the reference column. Forty-one lines remain. Six are payments to individuals. They become Person 1 to Person 6. She pastes the rest and asks for expense categories. The question still goes. No account details go with it.

For more ways to do this by hand, see how to redact sensitive data before pasting into ChatGPT. Payslips raise similar issues, covered in what to strip out of payroll data.

A decision list to hand to staff

Print this. Pin it up.

• Is it our approved business ChatGPT account? If not, stop.
• Is the header gone, with no name, address, sort code or account number? If not, stop.
• Are card numbers removed? If not, stop.
• Are personal payees swapped for labels? If not, stop.
• Is the reference column deleted? If not, stop.
• Do I only need categories or totals? If you need advice about the client personally, ask a manager.
• Not sure? Leave it out and ask.

AI is welcome here. Company and client data stay out of it.

Where software can help

Manual redaction works. It relies on people remembering every time, on a busy day.

Helio Guard checks each paste and file upload on AI sites in Chrome and Edge on Windows PCs. It takes out items such as UK bank details and card numbers and swaps them for labels, so the question still goes. It can also replace your own client names with a stand-in such as "Client A". Checks run on the PC with fixed rules. We never see what your team types. It is £1 a person a month, from 5 people, with 14 days free and no card needed. The details are on our pricing page.

Common questions about bank statements and ChatGPT

Is it a data breach if someone already pasted a full bank statement into ChatGPT?

Pasting a full bank statement into a consumer ChatGPT account may count as a personal data breach under UK GDPR, depending on the risk to the people named. Delete the chat, check memory, write down what happened and when, and ask your data protection lead whether the ICO or the client needs telling. Treat it as a learning point, not a disciplinary one.

Is a sort code on its own personal data?

A sort code on its own identifies a bank branch, not a person, so it is not usually personal data by itself. Paired with an account number or a name, it identifies a real account holder. Bank statements always show them together, which is why the sort code and account number should both come out before pasting.

Can I use ChatGPT Temporary Chat for bank statements instead?

ChatGPT Temporary Chat avoids saving the conversation to history, but OpenAI says Temporary Chats are kept for up to 30 days before deletion. On a consumer account there is still no data processing agreement. Temporary Chat is a sensible extra on a business plan, not a replacement for taking out account details and payee names first.

Related: Can I upload a client spreadsheet to ChatGPT safely? How to prepare the file first, Is it safe to paste NHS numbers or health information into ChatGPT?