Why this matters
The month-end bank reconciliation is where small mistakes hide. A deposit that never made it into the books, a bank fee nobody recorded, a bill entered twice, a check still in the mail. Matching forty rows against forty rows by eye takes an hour, and it is easy to tick a row that does not really match.
When the two balances do not agree, you cannot close the month. When you force them to agree, you can bury a real error.
In this module you give ChatGPT a bank statement file and a ledger export, have it list every row that does not match with a likely reason, and then write the reconciliation summary table. You check each exception yourself.
What you’ll build
A September reconciliation for Harbor Lane Studio, a made-up small design studio. Both files start the month at $48,210.37. The bank ends at $55,205.65 and the books at $50,835.15.
ChatGPT finds the four exceptions: a $2,315.50 deposit missing from the books, a $35.00 bank fee, a $1,240.00 duplicate bill, and an $850.00 outstanding check. The adjusted balances both come to $54,355.65, with a difference of 0.00, and each exception gets a one-line note on what to do.
What you need
- Nothing to start the practiceChatGPT is a practice copy and both files are already in the practice picker.
- A ChatGPT account that can read files, to do it for realUse a business plan and follow your firm’s policy for client financial data.
- The bank statement as a CSVDownload it from the bank’s website. Columns: date, description, amount. Delete full account numbers.
- The ledger export as a CSVExport the cash account detail from your accounting software for the same month. Columns: date, payee or memo, document number, amount.
- Both balancesThe opening and closing balance on the statement, and the opening and closing balance in the books.
Concepts
3 ideas you’ll use in the practice.
Match by amount and date, not words
The bank and the books describe the same payment differently, so matching on description fails. Tell ChatGPT to match on amount and date, allowing a few days apart.
Give it both starting and ending balances so it can check its own work.
Four kinds of exceptions
Missing from the books (a deposit nobody recorded), a bank fee, a duplicate entry, and a timing difference like an outstanding check. Ask for one table of every row that does not match with the most likely reason.
Tell it to write Needs review when it is not sure. Do not let it guess.
The summary must end at zero
A reconciliation is two adjustments that meet: the adjusted bank balance and the adjusted book balance. The difference should be 0.00.
Only a timing difference needs no entry. The others need a journal entry or a correction, so read each note before you post anything.
Practice
Do every step yourself in a practice copy of the real tool. It checks your work, and “Do it for me” finishes any step you get stuck on.
Do it for real
Now repeat it in your own account. Tick each step as you go.
Downloads
- Sample bank statement, September 2026 (.csv)The 40-row bank file from the lesson, made-up data.
- Sample ledger export, September 2026 (.csv)The 40-row books file from the lesson, with the four planted differences.
Quick check
3 questions to check you’ve got it.
1. Why match the two files by amount and date, not description?
- The bank and the books word the same payment differently
- Descriptions are always blank
- It is faster to type
Show the answer
The bank and the books word the same payment differently. The same payment can read “ACH CREDIT” in one file and a customer name in the other.
2. Check 1027 for $850 is in the books but has not cleared the bank. What do you do?
- Delete it from the books
- Nothing in the books, it is a timing difference
- Add it to the bank file
Show the answer
Nothing in the books, it is a timing difference. It is an outstanding check. It will clear next month.
3. What should the Difference line at the bottom of the summary be?
- 0.00
- The bank fee
- Whatever ChatGPT says
Show the answer
0.00. If it is not zero, there is an exception you have not explained yet.