Protect a file before sharing

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Using an AI assistant on your bank statements without sharing your private details

An AI assistant can show you where your money goes, and it does not need your account number or the names of the people you pay. This guide shows what to leave out of a bank statement, step by step, and how to check the file before you upload it.

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Maybe you want to know what your subscriptions really cost, why the month always runs short, or how much you spent on food last year. An AI assistant can answer questions like these from a bank statement in seconds.

A statement holds more than the assistant needs, though. It has your account number, the names of friends and family you pay, and little notes about what each payment was for. The good news is that the questions above only need dates, amounts, and a rough idea of what each payment was. You can leave the rest out, and it takes a few minutes.

Key terms

Statement export
a file you download from your bank's website that lists your transactions, usually as a CSV or Excel file.
Account number (IBAN)
the code that identifies a bank account. Your own is on the statement, and so is the account of anyone you paid.
Reference
the short note on a transaction, such as "Rent October" or "Thanks for dinner".
Stand-in
a made-up label used in place of a real name, such as PERSON_001.

What is on a bank statement besides the amounts?

What What it shows
Your name and address Who you are and where you live
Your account number Your bank and your account
Names of the people and companies you pay Friends, landlord, doctor, employer
Their account numbers Accounts that belong to other people
References The reasons for payments, in the sender's own words
Shop and town Where you were, and when
Balance How much money you hold

Only two of these, the date and the amount, matter for most questions about spending.

What does the AI assistant need?

Start with your question. If you ask "how much do I spend on groceries each month?", it needs the date, the amount, and a way to tell groceries from everything else. It does not need your address or anyone's account number.

Is my account number a secret?

Not in the way a password is. ING, a German bank, says in its guidance that an IBAN is "not a secret PIN". People need it to send you money, and having it does not let anyone into your online banking, which asks for a password and a confirmation for each transfer.

It does add that someone with only the number could try to collect money by direct debit. So it suggests that you look through your account for payments you do not recognize, and that you share only what a payment needs. An analysis of your spending needs none of it, so leave your account number out. Banks in other countries have their own rules, so check your own bank's guidance on how long you have to dispute a payment.

What do the notes on my payments give away?

References are often the most personal part of a statement, because they are written in ordinary words. "Dr Svoboda, physiotherapy" says something about your health. "Monthly donation, church" says something about your beliefs. "Loan repayment to Petr" says something about a friendship.

You may be happy for an assistant to know that. Most people would still like to decide that for themselves. Because these notes are free text, a search for names will not catch them all: a note can hold a nickname, a first name, or a name in another order. Reading the longer ones yourself is the most reliable check.

What about the other people on my statement?

Each payment to or from someone else shows their name, and often their account number. They did not ask to be part of your analysis, so it is kind and sensible to replace them. A label such as PERSON_003 works well, because it stands for the same person every time. You can still ask "how much did I pay this person over the year?" without anyone being named.

How do I protect the file?

  1. Download your statement as a CSV or Excel file from your bank's website. A PDF holds a page, not a table, and DataAttendant does not open it. The guide on which files DataAttendant can open explains the formats and what to do if accents look wrong.
  2. Delete the columns you do not need, usually your account number, your address, and the balance.
  3. Replace the name of each person with a stand-in. Use the same one every time that person appears. See replacing real names with consistent stand-ins.
  4. Read the references. Remove the column, or replace the parts that name people and places.
  5. Keep amounts and dates exactly as they are if you want correct totals. Rounding changes the sums.

How do I check what is left?

Can I read the answer in terms of real people?

Yes, if you kept the list of which stand-in replaced which name. When the assistant says "PERSON_003 received the most", you put the real name back on your own computer, and the assistant never sees it. See putting the original values back after an AI answers.

What does the AI service do with my file?

That depends on the service, your plan and your settings, and it changes from time to time. The article on what data should not go into an AI tool lists what to look for in a provider's current terms.

How can DataAttendant help?

DataAttendant is a tool that runs in your web browser, on your own computer. You open a CSV or Excel file. It looks for names, account numbers and other personal details, and suggests what to do with each kind. It shows you a preview and a list of what is still in the file before you download your protected copy. You make every decision. It cannot find everything, so the checks above are still worth doing. Your file is processed in your browser and is not sent to DataAttendant. How DataAttendant works shows the steps.

Sources

  • ING Germany, "IBAN weitergeben: riskant oder kein Problem?", ing.de/wissen/iban-weitergeben. Read 28 October 2026. It is one bank's guidance for German accounts, and its refund deadlines are those of Germany's direct debit rules. Other countries differ.

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